My favorite virus here sality.
I've been infected by this virus 3 times in last few years but never able been to disinfect it. I had KAV in 2007 it failed to disinfect it
then in 2009 I had norton it wasn't able to disinfect it.
& in 2011 I was infected with it to remove this virus I ran Quickheal Boot Scan 3 times still it wasn't able to disinfect it.
This virus is a polymorphic file infector. It keeps on injecting it codes in every executable file in the pc. It keeps on continuing the never ending process.
As it is a polymorphic virus it re-generates everytime it is deleted.
I would only advise doing a reinstall of windows in this situation. If you still wishes to give a last try to clean it try using these:
1. Download Win32/Sality Remover 1.2.0.616 Free - A useful tool for deleting the Win32/Sality virus from your computer - Softpedia
2. How to disinfect my computer from Virus.Win32.Sality?
Another way to disinfect is to remove the payload code in last line of every infected file.
I may analyze your system if you provide these logs:
1. HJT Log
2. MBAM Log
3. OTL Log
4. GMER Log