If possible, could you please list all of the scans that you have tried?
As your scans do not work at all download 'Rkill' from a 'clean' PC. The post by Grif Thomas explains how to use it ( http://forums.cnet.com/7726-6132_102-3203485.html ) Remember that you cannot restart the computer until you run all of your scans!
Try to do your scans in 'safe-mode' or 'safe-mode with networking'. You might find the malware that way.
Try the program 'Hitman Pro'. It is a 30-day trial. However it uses multiple program scanning tech to look for malware and remove them.
Hope this helps,
When i turned on the computer, a screen shows up on my desktop saying "YOUR SYSTEM IS INFECTED! System has been stopped due to a serious malfunction. Spyware activity has been detected. It is recommended to use spyware removal tool to prevent...". I ran AVG, malware, etc... and nothing works. Should I reformat the hard drive and start all over with Windows XP? Any help would be greatly appreciated?