First of all if you are decideing to reformat the harddrive than you wont want to do what im giveing to you. But if you want to try to clean, stop running programs and see if you can get this computer cleaned up and running than follow these steps:
1. The command you are looking for is Start/Run/Type: MSCONFIG
Than click on the startup Tab and continue to uncheck the programs you feel are not needed. (Be careful and make sure that you dont need the programs that you are going to stop, i.e. yahoo messanger, real networks, aim, msn messanger etc.. you might want to stop these types of running programs)
2. Since you have run AdAware SE and I would recommend that you update and do a full system scan again for this threads purpose. Now I want you to download a software called Ewido at http://www.ewido.net/en/
if that link doesnt work go ahead and google it, obtain the 15 day free trial, check for the updates in the commands once you download and open up Ewido, than do a full system scan and choose to remove/delete for any things that pop up, this is a great program for eliminateing spyware and malware and any other vicious trojans or worms.
3. Now for a deep clean of the computer. Im sure you have tried to manually remove files etc... I know of a program that is a great clean up tool. Its called Cleanup4.0! Heres the website to download this program heres the direct download and website http://www.stevengould.org/downloads.../CleanUp40.exe
once again if you have trouble google it and find it. Once you download it open it up and in the options I want you to first check the following: Empty recycle bins, delete newgroup cache, delete newsgroup subscriptions, delete cookies, delete prefectch files, and cleanup all user. Hit ok and than Cleanup! This will flush out a lot of files or ones you couldnt get to reboot when told on finish. Than do it again but this time go to options check everything but if you want to keep your favorites and bookmarks keep that unchecked press ok and cleanup than reboot on finish when told.
4. Now what you can do since I dont know the type of Operating system you are useing you would want to do a disk defragmentation. That can be found at Start/Programs/Accessories/System Tools/Disk Defragmenter
If you need help with a Virus program etc... let me know, and if the computer still remains to act funny after these steps write me back and I will introduce you to a HiJack Log..Hope this helps
P.S. Make sure to check for OS updates too...