Malware infection - Help!

My desktop computer got infected with a virus that has completely hijacked both IE and firefox - I can't download anything helpful from this machine - can't get hijackthis,exe, spybot, or any of the other cleaners recommended in the cleaning steps to help me. I was able to run microsoft malicious software removal program which reported infection from two trojans - Reno and something else ....I found the malware step by step on your forum, but can't get past the run cccleaner step (I used the portable version I downloaded with my laptop) and now I don't know how to proceed - arghh! Machine is a Dell XPS 400 running windows XP 5.1, SP3) Of course cccleaner removed the mrt log, so I am running again to try to get exact names it reports. I also have a pop-up warning of spyware infection using the "ervent data loss" message, which sounds like SpySheriff to me. Any assistance much appreciated.

 

Thanks for writing back - I found sdfix, which I was able to do load and run after transferring it via a flashdrive. That cleaned it up enough to allow me to use the internet and successfully download the remainder of tools I needed. thanks for the comprehensive instructions - they are a great help!