Mark writes in with a troubleshooting question Question:When turn my computer on all I get now is black screen that says "file missing or corrupt" System32\drivers\isapnp.sys. Attempt to repair by starting Windows setup using the original setup CD-ROM. Select R at first screen to start repair.
This is homemade computer from an old company use to work for so don't have any disk. I did find a disk titled Intel Express Installer, but when I put in the computer nothing happens.
Answer: There are several things that can cause a problem like this from a virus issue to a corrupt file. One thing to check is for a misc .sys file that is 0 bytes in size in your System32 folder and delete it if you find it. If you have such a file then it is a sign of a virus problem. This will require using the Windows Recovery Console to look in the System32 directory as well as knowing basic command line commands.
You can also use the Recovery Console to replace the isapnp.sys file with a good copy off of the CD to see if that fixes it. If you cant find it on the CD then you can get a copy from another computer with Windows XP and copy it over while in the console.
If nothing seems to help then you can try a repair installation of XP which will reinstall Windows over itself and leave your programs and files intact. Just be sure to follow the instructions carefully to avoid doing a fresh install and deleting your data.