How to Fix Windows XP With Missing or Corrupt System Files

1. Start your computer up and log into your Windows XP operating system with an administrator-level user account.
2. Insert your Windows XP CD into your CD drive and close any popup windows that may appear.
3. Click on the 'Start' button, open the 'Run' utility, type 'cmd' and then press the 'Enter' key.
4. Type 'sfc /scannow' into the command prompt and wait while the scanning utility checks your system files for damage or deletion. If any bad files are found, they are automatically replaced.