Set your bios to be able to boot off the cd.
Insert your CD and press any key, when prompted, to get the computer to boot off of the CD
Check yes for the agreement.
Choose repair.
Computer will run for approx 37 minutes. You might think that you will lose things. If you think you will, then back up your files. I didn't lose anything. It will repair your computer to have all the origional Windows componets.
Follow the instructions, then it will prompt you to restart your computer.
Then remember you will need to go to Microsoft for your Windows updates.
***You will have to be the Administrator to do this***
Hope this helps.
Rick
I have many problems. I had some spyware. After I used Ccleaner, I could no longer access my mail from Yahoo or Hotmail. I can access my mail from Netzero. I cannot update Windows. Although I am using Windows XP Home, with service pack 2, when I tried to download IE7, I receive a message that tells me that my system doesn't meet the minimum requirements to dowload IE7. I tried installing Firefox, and something is preventing from running on my system. I did a system restore. That didn't help.
I hope someone can help me. Thank you.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic