OS instability

Here's my problem: When i boot my pc running XP home edition all of the Windows generated text appears encrypted. I've tried restore and it will not restore me to an earlier time. Norton antivirus registers no infected files. Can you offer any suggestions to remedy this? It sure is acting like I have a trojan horse of some kind.
Thanks for any help you can offer.

Neal,

How about safe mode, does this issue also occur in safe mode? Information about how to boot the computer into safe mode can be found on the below document.

http://www.computerhope.com/issues/chsafe.htm

If the computer does not have this issue in safe mode it could be possible that your computer may have a improper setting for your video card that is causing this issue or that another computer program was installed that caused this issue to occur. Verify your video settings by opening the display icon in control panel and try uninstalling any recent programs through the "Add/Remove Programs" in control panel.

Finally you may also wish to update your video drivers. A listing of video drivers can be found at the below page.

http://www.computerhope.com/drivers/video.htm

If you continue to experience this issue after trying the above recommendations feel free to continue posting on this thread until we get you resolved.