Isapnp.sys file is missing or corrupt
Windows could not start because the following file is missing or corrupt:
\windows\System32\Drivers\Isapnp.sys
RESOLUTION
To resolve this issue, use Recovery Console to replace the Isapnp.sys file.
To replace the Isapnp.sys file in Windows XP, follow these steps:
1. Start the computer from the Windows XP CD-ROM.
2. At the Welcome to Setup screen, press R to repair, and then press C to start Recovery Console.
3. At the C:\Windows prompt, type the following command, and then press ENTER:
ren c:windows\system32\drivers\isapnp.sys isapnp.old
4. At the C:\Windows prompt, type the following command, and then press ENTER:
expand cd-romdrive:\i386\isapnp.sy_ c:\windows\system32\drivers\isapnp.sys
For example, type:
expand d:\i386\isapnp.sy_ c:\windows\system32\drivers
5. After the file is successfully expanded, type exit, and then press ENTER to exit Recovery Console.
6. Restart the computer.