How to Restore Rundll Files to Windows XP

1. Place your Windows XP installation CD in your CD-ROM drive.
2. Click on your 'Start' menu (the lower-left icon on your screen with a Windows logo) and click 'Run.'
3. Type 'expand D:\i386\rundll32.ex_ C:\windows\system32\rundll32.exe' and click 'OK' near the bottom of the dialog window. Replace 'D' with your CD drive's letter and 'C' with your system hard drive's letter. This places an authentic, uncorrupted copy of 'rundll32' in your system.
4. Restart your computer.