If you use the Windows XP Home Edition, see our special installation tips.

Common Computer Problems and Solutions

PROBLEM: Non-system disk or disk error. Replace and press/strike any key when read.

Explanation: The system found a boot device--either a floppy disk or a hard disk--and tried to boot it, but could not start the operating system because the operating system files are not on the booted volume.

Diagnosis: The most common cause of this problem is trying to boot a non-bootable floppy or hard disk, that is, a disk that has not been made bootable using the "FORMAT /S" or "SYS" commands. If this occurs on a disk that was already prepared to be bootable, it means that the operating system startup files have become corrupted.

Recommendation: If trying to boot from a floppy disk, replace with a bootable disk and try booting again. If trying to set up a new hard disk, first set up the hard disk so it is bootable. If this type of error is encountered in an existing system, there is a good chance that the disk has become corrupted somehow.

PROBLEM: Invalid media type

Explanation: The system tried to use an incorrect disk or other media.

Diagnosis: This is one of those poorly phrased messages. It almost always means that you tried to use a hard disk volume after partitioning it, but before formatting it. For example, if you are setting up a new system and you partition the hard disk, then boot from a floppy and type "DIR C:", you will usually get this message. The system looks for a media type descriptor on the hard disk and does not find what it expects, and produces this message.

Recommendation: Assuming that you are setting up a new hard disk, just format the disk and you are all set. If an existing disk produces this error, then it means that something has seriously corrupted the disk.

PROBLEM: I am experiencing file system corruption problems, such as lost clusters, cross-linked files or invalid files or directories.

Explanation: While performing routine file system scans, errors are being detected on one or more disk volumes. These errors are usually lost clusters or cross-linked files. Compression errors on compressed volumes are discussed here. The disk itself otherwise works fine although a handful of files might be corrupted, the disk is corrupted to the point of unsuitability, or the contents appear scrambled.

Diagnosis: A small number of file system problems is normal on just about every PC, depending on what kind of operating system and software you are using. In particular, lost clusters are common because any time an application crashes or there is a power outage, in fact any time an application is interrupted, it may leave behind partial files that show up as lost clusters because the file was never completed properly. However, finding large quantities of lost clusters even when scanning regularly, or repeatedly finding problems like cross-linked files, invalid files or directories, can be a signal of a more serious problem. (Note: A lost cluster is not the same as a bad sector, which is a physical disk problem, not a file system problem.)

Recommendation: If this problem occurs, you may want to try all of the following:

• Make sure you thoroughly scan your disk for viruses, using an up-to-date virus scanner. Corrupting the file system is a popular game with viruses.
• Make sure that you are using the correct type of disk utilities. Using a disk utility that is not designed for Windows 95 on a Windows 95 system, or using one not aware of FAT32 on a FAT32 volume, will cause the program to detect "errors" that don't really exist. They just don't properly understand what they are looking at because they are out of date.
  
• If the problem recently occurred after installing a particular piece of software, that program may be causing the corruption. Some applications can be buggy, especially if they crash a lot; they may leave partial files and other file system anomalies lying around. Try not using the suspect application for a few days if possible, and see if the problems go away.
  
• Make sure that you employ proper shutdown habits. No PC running any version of Windows should be shut down without following a proper shut down procedure.
  
• If you are using Windows 3.x, look for old stray .TMP files in the temporary file directory (which is often specified with a "SET TEMP=<directory>" command in your AUTOEXEC.BAT file) and delete them. These files cause system problems sometimes if they are allowed to accumulate.
  
• Check for resource conflicts. These can cause files to be corrupted.
  
• You may have an instability problem with your operating system installation. You may want to try reinstalling the operating system. A recently changed driver may be the problem. If you have recently installed bus mastering IDE drivers, these could be causing the problem. Try uninstalling them if possible.
  
• You may have a real problem with the disk that is causing the difficulty. It isn't too typical to find repeated file system problems without a real disk problem manifesting itself in other ways but it is possible.

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