Hi! Welcome to the TechSpot forums!
The infection that you can see in the ESET online scan,
Sality is what we call a file-infector.
These are particularly malicious, in that they infect all of your
legitimate programs.
The problem is... the virus is very buggy, so it does not do a good job of infecting your files, so any attempt to disinfect and possibly save your files would be futile, in that, due to the buggy virus, we cannot properly disinfect your files.
What I highly recommend now is a reformat and a reinstallation of Windows XP.
Please let me know if you are prepared to do so.
You may backup and save all files except programs (meaning pictures and documents are okay), because if you backup any applications, they will transfer to your clean system, and you will be reinfected.
So, with that said, do you have your Windows XP CD?
Guide for format and reinstall:
http://www.helpmyos.com/tutorials-s...-operating-system-the-easy-way-t1307.htm#3143
If you would like to try to disinfect the system anyway, no promises, but I can do the best I can possible.