Disk Errors

The storage of files and the ability to access this storage of material is essential to regular computing activities.  This article speaks to issues related to the physical storage of data and to performance concerns.  Free disk space and hard disk issues are a central focus.  Recommendations are presented on how to troubleshoot and enhance the functioning of the computer hard disk drive.

A Definition

To begin we need to clarify some of the terminology and concepts presented here.  A hard disk drive (HDD) is the device mechanism involved in the storage of data.  It controls and provides access to the reading and writing of data stored on your computer.  The “hard disk” is the actual storage medium – the physical disk.  In the 1990’s it was common for all personal computers to also have a floppy drive so that 3.5” and 5.35” floppy disks could be used as a secondary storage medium.  Advances in computing have evolved and computer users have made the move to CD’s and DVD’s which have considerably more storage capacity.  Floppy drives have less than 1 MB (megabytes) of space and DVD’s have 4.7 GB (gigabytes). 

While hard drives are an internal component to your computer system, you can also use external hard drives to supplement your data storage needs.  External hard drives are connected using a cable interface such as USB or FireWire.  These hard drives are reaching capacities over 1 TB (terabyte); that is, one trillion bytes or 1000 gigabytes.  A byte is a commonly used unit of measurement in computing that consists of eight bits – a binary digit that is either 0 or 1.

Considering the holding capacity of information on these devices, it becomes important for you to be aware of the type of file system your computer uses.  A file system is a particular method used for organizing data.  For example, there are flat systems that do not use subdirectories and there are file systems that utilize a hierarchical system.  One common file system is FAT (File Allocation Table).  Although it has been commonly used especially with system prior to Windows 2000, it is prone to fragmentation.  The subject of fragmentation is covered in more detail later in this article. 

The standard file system used with Windows 2000, XP, and Vista is NTFS (the New Technology File System, named after Windows NT).  While there are some limitations to this file system it is considered an improvement from its predecessor.  For example, it utilizes a Master File Table that reduces the occurrence of fragmentation.  Microsoft supplies a conversion executable to convert previous FAT file systems to NTFS.  This is a one-way process – if you want to revert the process you have to completely reformat your hard drive.  See their support article for more information: http://support.microsoft.com/kb/307881/EN-US/.  For the purposes of this article we will refer to primarily to Windows XP systems utilizing NTFS file system.

Available Hard Disk Space

If your hard disk free space is 10% or lower, your will begin to notice issues related to performance degradation.  The simple act of moving files from one location to another requires free disk space.  Daily activities such as surfing the web requires that there is available disk space so that files can be temporarily downloaded to your system including all the graphics you see on a web page.  Another reason your computer requires free disk space is that it uses a virtual memory system.  This involves swapping data between RAM (Random Access Memory) and disk storage so as to allow for multi-tasking, greater memory allocation, and speed of accessing information.  For more information on virtual memory see our article: http://www.fix-pc-errors.com/virtual-memory.htm

As a result of these factors, free disk space is of primary importance.  There is one basic theme that is touched on repeatedly here: free up disk space or add disk space if you are experiencing a shortage.  To determine how much space is on your hard drive you can do the following:

1. Open Windows Explorer or double-click the My Computer shortcut on your desktop.
2. Right-click on a disk drive as distinguished by the disk icon. 

A disk drive icon will appear as:

Windows XP:       

Windows 95, 98, and 2000:

3. Select the Properties option.  The Properties dialog will appear as follows:

There is useful information presented in the properties dialog including: total capacity, used space, and free space.  The type of file system is depicted near the top (NTFS in this case). There are some disk property options to choose from as well.

Disk Property Options

Compression

Disk compression is an option that enables you to compress files to free up disk space.  There are trade-offs with this alternative so you will need to understand what is at stake and what conditions are best suited for compression.  The process of compressing data involves using fewer bits to store the same binary information.  This involves first encoding the file and then decoding it.  Although, computers these days can handle this process more efficiently, it can be time-consuming.

Recommendation: while this saves disk space it is not advisable in most situations as system performance is degraded.  Also, while you can password-protect the compressed item, compressed files and folders cannot be encrypted on an NTFS system. 

Rather than compressing an entire drive you can compress individual files or folders and all items stored within the folder.  To compress an individual folder do the following:

1. Open Windows Explorer and locate the folder or file.
2. Right-click the item and select Properties.
3. On the General tab, click the Advanced button.
4. Check the Compress contents to save disk space option.
5. Click OK.

Some files are already compressed and there is no space gained in trying to compress them further.  For example, zip files, mp3 files, and many image and video formats are already compressed.  With this in mind, there are situations that warrant compression including those files that are in an uncompressed or native state.  We suggest using compression for non-compressed files in the following instances:

-          before recording files to a CD or DVD if space is a concern, and

-          before transferring large files over the network as this will save time and bandwidth.

Indexing

The Index Service is a utility that is available for speeding up file searches.  The content and the properties of the files are indexed for faster search results.  This service is dedicated to the process of filtering, creating index entries, and cataloguing entries for searches.  As can be seen with the Local Disk Properties image above, the Index option is on by default.  There are some Internet authors on this subject, who state that this can slow your computer’s performance as the service is constantly running.  However, considering the speed performance of many CPU’s today, the performance constraint is negligible.

As with compression, you have the option to choose individual files or folders by doing the following:

1. Open Windows Explorer and locate the folder or file.
2. Right-click the item and select Properties.
3. On the General tab, click the Advanced button.
4. Do one of the following:

• For folders, check the option: For fast searching, allow Indexing Service to index this folder.
• For files, check the option: For fast searching, allow Indexing Service to index this file.

5. Click OK.

While the Indexing Service is on by default for the entire hard drive disk, you can turn it off and index only items you want.  Microsoft recommends to not index the entire disk drive with Windows Vista.  They state that if the index is too large, routine searches will be slower as the index will not perform well.  Their recommendation is to only index folders that contain your personal files.  For information on indexing in Microsoft Vista see: http://windowshelp.microsoft.com/Windows/en-US/Help/68dd14f2-a9cb-4134-a076-b8abb011a1f61033.mspx#EAG.   If this is true for Vista, one has to question that this would be true for previous operating systems as well.

Disk Space and Disk Cleanup

There is an internal Microsoft tool that is dedicated to cleaning the hard disk drive.  By clicking the Disk Cleanup button in the Properties dialog as seen above, your initiate a hard disk drive examination.  Usually you will have to wait just over a minute or two and then the Disk Cleanup dialog is displayed:

As can be seen here, there is a list of items that can be deleted.  Each of these can be selected and you can find out more about them using the description that is displayed in the bottom half of the dialog.  Typically this list is comprised of temporarily stored files and items that have been “deleted” but are actually moved to the Recycle Bin.  The reason there is this intermediary process when deleting items is that you can still restore items you have accidentally deleted.   With the Disk Cleanup utility, you can decide what you want to permanently remove from your system by checking the boxes of your choice and then clicking the OK button. 

Recommendation: There are drawbacks and limitations to this tool.  Our recommendation is to use a third-party application called ParetoLogic Privacy Controls.  This handy application is designed to detect temporary items, cached items, history and pointers, Internet cookies, and other items that clutter your system.  You can choose to remove any or all of the items that have been detected.  You also have the option to “shred” files using a overwrite technology so that they cannot be restored.  There are safeguards so you do not remove system files.  This tool is very good at not only cleaning your system but also removing unnecessary and unwanted clutter.  To download this application, click here: Privacy Controls

Defragmentation

Once you have thoroughly cleaned your hard disk drive you will want to perform a defragmentation.  By doing so, items remaining on your system are more organized and the files that you download and install will be less prone to fragmentation.  Fragmentation occurs as a result of the operating system segmenting files to fit them in allocated spaces on your disk drive.  This is to make use of space that is made free when files are erased.  There are other instances when a file is modified and may require more space to accommodate the change.  The less free space you have on your system the more fragmentation occurs. 

Your computer system can suffer some loss of performance due to fragmentation.  However, this is difficult to notice as the seek time is very fast.  “Seek time’ refers to the time it takes to locate the data.  The typical seek time for a personal computer is usually about 10 milliseconds.  This concern related to performance is covered in more detail in the article on defragmentation.  For more information follow this link: http://www.fix-pc-errors.com/defragmentation.htm

Disk Error Checking and Repair

Errors with respect to hard disks come in various forms.  Like a good medic or technician your first point of order is to determine what the problem is.  Understanding what issues are at hand is an integral part of coming up with a solution and in saving time and effort. 

Diagnosis

To begin, you will need to narrow down the possibilities by determining if the potential failure is physical or logical.  If the physical mechanics of the drive are failing there will likely be some physical indications.  Examples of physical symptoms include louder-than-usual whining sounds, clicking, or ratchet-like sounds.  If this is the case, you could be experiencing a failing hard disk and you need to back up your files and critical data immediately.  After backing up your files, you can prolong the life of the hard disk as best as possible by running your computer only when necessary while coming up with a fix.  We suggest you contact the manufacturers of the hard drive or your computer system vendor.

If you are running a Windows 9x system (Windows 95, 98, or Me), you can refer to this article: http://www.brienposey.com/kb/hard_disk_failure_1.asp.  For more recent systems, we suggest going to the Microsoft site.  There are difference with how previous systems boot up and how Windows NT, 2000, and XP start up.  See this article for more information on troubleshooting startup issues:  http://www.microsoft.com/mspress/books/sampchap/6795.aspx.

If the symptoms are related to logical issues than you will experience error messages or issues related to the running of your programs or difficulty starting the computer.  Of course, a good technician needs good tools to gain an accurate picture of what is going on.  One tool that is a good starting point in some cases is the Disk Management tool.  If your system provides this tool you can access it by doing the following:

1. Click the Start button in the taskbar, and select Run.
2. In the Open box, type: diskmgmt.msc
3. Click OK.

The Disk Management tool is displayed:

The size of the disk and partition is displayed as well as the type of file system.  You can get an idea if your drive is online and active and you can view the status of any connected drive – internal, external, or USB device.  There are a variety of status labels that can be displayed if the Disk Management utility discovers an issue with the disk or for some reason does not detect the disk.  Status label examples include: Foreign, Missing, Not Initialized, Offline, Online (Errors), Unreadable, Failed, Healthy (At Risk), Healthy (Unknown Partition), and Unknown.  For a description of what these are and instructions on what to do we recommend that you go to the Microsoft site: http://www.microsoft.com/germany/technet/prodtechnol/winxppro/reskit/c28621675.mspx.  There is a lot of information in this article.  You can link to the section on Disk and Volume Status Descriptions. 

Microsoft lists a variety of conditions that you could be facing including hardware issues, power outages, malicious items (malware, spyware, etc.), and human error.  Corruption of files is a logical failure condition and, in this category, we can also include Master Boot Record (MBR) failure, Boot Sector failure, cross-linked files, and bad sectors.  The first two relate to startup issues and Microsoft suggests you first determine when the problem occurs – before, during, or after the startup sequence.  Once you have a better sense of what is going on with your computer you can begin to look at possible fixes including when and how to apply them.

Treatment

If the issue is related to the startup process, there are a variety of possible causes.  Microsoft states: “The root cause of startup failure, including contributing factors, can stem from a variety of problems, such as user error, application faults, hardware failures, or virus activity.”  If it is a serious condition such as in the event that the system files are corrupt, you may need to restore the files to their original state. 

If you can start your computer but you feel that there are likely infected files, you can restore it to a previous state by doing the following:

1. Disconnect your computer from the network/Internet and disable any anti-virus programs.
2. Click Start and select Help and Support.
3. In the Pick a task section, click: Undo changes to your computer with System Restore.
4. With the setting: “Restore my computer to an earlier time” selected, click the Next button.
5. Continue to follow the steps until your system is restored.
6. Re-enable your anti-virus protection and connect to the network/Internet.

You can refer to the following article: http://support.microsoft.com/KB/831829 for more information.

If you have difficulty starting your computer, before or during the bootup process, you can use the Recovery Console available with Windows XP.  This can be done using backups or the Windows XP installation CD.  With earlier operating systems, you can use a floppy boot disk.  The Windows 9x link above describes how you can make a bootable disk if you do not have one supplied when you first purchased your system – refer to the hard_disk_failure article above.  With XP systems you can enter the CD and follow the directions related to repair.  You will need to have administrator privileges as you will be prompted to enter the password and it is useful to have some experience with computer systems.  For more information on using the Windows XP Recovery Console see: http://support.microsoft.com/kb/307654.

If the corrupt files or infected files came about as a result of a virus attack or malicious software then you need to also perform system scans to remove the intruders.  Until the malicious items are removed you could come across the same issues again and again.  Malware – the term used when describing malicious software – is a common experience.  Studies conducted by the National Cyber-Security Alliance have proven revealing.  Of the computers tested in this study, 80% had malware items.  What is even more surprising is that there was an average of 93 items found on the computers and the majority of the computer owners (89%) did not know their systems were infected.  Many of these items are designed to install in the background, to reside on your system, to operate automatically, and without being noticed. 

We recommend downloading and running ParetoLogic Anti-Spyware so that you can detect these items that are on your system.  This program also offers protection from malicious items before they infect your system using monitoring technology.  Malware can infest your system when you surf the web and all you have to do is click a web link or browse to a site.  ParetoLogic Anti-Spyware offers a thorough scan of your system and removes all traces of detected malware items.  There is backup functionality and you can schedule scans to occur on a regular basis.  These scans are fast and won’t tie up you system resources. 

Other Logical Failure Fixes

If you can start your system and you are experiencing issues with the functioning of your hard disk drive you can check for errors on the disk.  While this can be considered a logical failure there are physical considerations to take into account.  Most hard disks have a basic shared structure and we will need to delve into the specifics of this in a bit more detail.  To begin, a hard disk has one or more spinning platters that are used for storing data.  These turn in place so that all areas can be accessed.  Both sides of the disk are electromagnetically charged and data is written to these by mechanisms called read-and-write heads, or read/write heads.  There is typically one head per side.  This is where data is written, stored, and accessed.

The actual space between the head and the disk platter is considerably minute.  It would only take a fingerprint or a particle of dust on the disk to disable the disk from spinning.  If the disk is incapable of spinning the read-and-write heads come to rest at what is called a landing zone.  The term is also used when the heads come to rest when you power down your computer.  However, if the disk is frozen in a landing zone, you can contact your manufacturer but it is Iikely that the disk is not recoverable and it would take considerable cost and effort to recover the data.  This is why regular backing up of your system is vital.  Check out the free Microsoft tool SyncToy – it synchronizes your backups quickly and easily.  Search for the program and download it by clicking here: http://www.microsoft.com/downloads/.

When situations arise where error messages are displayed or system crashes occur, disk errors can be the cause; more specifically, it can be a result of bad sectors.  Sectors of a disk can become damaged to the point that they are no longer usable.  This is a troubling situation but it does not mean that the entire disk is unusable.  In fact, it is not uncommon to have new hard disks shipped from the manufacturer with bad sectors.  When a section of the disk is identified as a “bad sector” it is marked by the system as unusable and these areas are skipped and no longer used to store data.  If this situation occurs after you have saved data to the disk and you are looking at recovering the data, you will need to use a third-party application to recover the information.

Physical errors known as bad sectors are identified as such when using the error-checking tools such as Scandisk and Chkdsk.  See the article on Chkdsk for more information on how to use this system tool          ( http://www.fix-pc-errors.com/chkdsk-definition2.htm ).  This disk utility checks for problems such as directory errors, cross-linked files, clusters that are considered “lost clutters”, and input/output errors (I/O errors that relate to transfer of data from the computer to peripheral devices such as the monitor or keyboard).  By running this tool you can detect disk errors and you can choose to “repair” them by selecting the required settings.  You need to have administrative privileges to run and repair disk errors.  When the system repairs the bad sectors it effectively remaps them and it does it in such a way that is transparent.  In fact, a file system that is NTFS can detect bad sectors and dynamically remap the cluster by allocating a new cluster for the residing data.

Some information available on the Internet suggests that when bad sectors are detected by the system, it is an indication that the disk is failing.  As mentioned, a bad sector is a common condition even when purchasing brand new disks from the manufacturer.  However, if this is an ongoing condition and begins to happen consistently or repeatedly, then you would be best advised to back up your data and move your files to a new hard drive.  The costs of hard drives have gone down considerably in recent years and the storage size of new drives has increased.

Other treatments of hard disk drives include reformatting the drive.  This is an involved process and warrants a separate article unto itself.  You can refer to this article by Webopedia: http://www.webopedia.com/DidYouKnow/Hardware_Software/2005/harddrive_format.asp.  Reformatting your hard disk drive is a difficult process.  It involves backing up all you data, ensuring that you have copies of all your application and system installation CD’s, “wiping” the drive completely, and reinstalling everything.  There are those that do this on a regular basis so that their system can once again arrive at a “like new” level of performance.

For these users there are two major reasons for doing this – to wipe out malware and to clean up all the clutter that clogs the system.  This is worth mentioning here for two very important reasons.  For one, as has been mentioned throughout this report, free space is vital to good functioning of a computer.  Secondly, corruption of files and improper functioning of a computer can be the result of malicious programs running on your computer.  We have provided one recommendation about removal of malware.  We have another recommendation related to removal of unwanted items.

Clutter and Free Space

There have been numerous references to free disk space including using the Disk Cleanup utility, using disk/file compression, and the potential issues that can arise from having less than 10% free disk space.  Once you are down to 10% disk space, you might find that you are in a constant battle of determining what you should keep, what you should store on alternate back up devices, and what items you can download and install.  There is a perpetual struggle for space and keeping the system free of clutter. 

The second issue many people face these days relates to security of information.  More and more we find that there is data that can be accessed without consent or approval.  As computers have become more sophisticated there are more and more shortcuts related to making it easier for us to enter usernames and passwords to web sites.  Personal data and Internet cookies are stored in many areas of our computer system and sometimes “delete” does not necessarily mean complete removal of data from the hard disk (as mentioned earlier).  In fact, there are studies that show that discarded or resold hard disks contain valuable or personal information.  In one study reported by PC World, there were nine out of ten salvaged hard drives (drives that were discarded) that had sensitive information on them.  In another study by Olaf Kehrer, it was discovered that 113 out of 200 drives purchased on eBay had confidential information on them.

We recommend that you utilize a program that accomplishes two objectives: removes unwanted clutter from your machine and detects and removes sensitive data.  One such program is ParetoLogic Privacy Controls.  It has numerous features that include thorough scanning of sensitive information and clutter, secure deletion, the option to shred files using overwrite technology, and built-in safeguards so that you have an idea of what it is you are removing beforehand.  To try the software click here: Privacy Controls.  Don’t forget that once you have some new free space available you will want to run the defragmentation utility as stated earlier.

We have included a lot of information on this subject here as matters concerning the hard disk drive are numerous.  Fortunately there are tools available on your system and from trusted manufacturers that can assist you in running a clean and efficient system.