1. Insert the Windows Recovery CD into the computer's DVD/CD drive, and start the computer.
2. Select a key when prompted by the computer to 'Press any key to boot from CD.'

3. Select the 'R' key when prompted to repair or reinstall the operating system. Then press 'Enter.'
4. Input the administrator password for your computer when prompted, then enter 'cd c:\windows\system32\config' at the DOS prompt. Enter 'copy\windows\repair\system' at the next prompt to permit the Recovery CD to copy files to your computer.
5. Remove the Recovery CD from the drive. Restart the computer to complete the operating system repair.