My Computer is infected, don't know what to do

[SourceCode]

I am running Windows Xp.

The problems are...

1. I have a little yellow yield sign in my toolbar with an exclamation mark. Every once in a while a little popup appears from it saying I have spyware. If I double clik it a webpage opens up that says I have spyware.

2. My desktop is flashing white and offwhite, repeatedly.


I have tried...

1. Using Ad Aware, some stuff was removed with it.
2. Using Search and Destroy, some stuff was removed also
3. Using housecall, some viruses were removed, one was not
4. Using avg, about 7 viruses were removed, it won't detect anymore
5. Microsofts anti spyware program


I don't know if I still have a virus or not. I'd like to avoid reinstalling windows because I have a ton of stuff to backup. What are other virues scanners or spyware removal tools I can use that are free?


EDIT********************************************

I give up, i'm backing up my files and reinstalling. Sorry for the post, delete it if you want.