HERE is your "evil" file;gaopdxserv.sys it is a Trojan/Backdoor
From what I see on that SDFix log, there is or has been a LOT of P2P file sharing going on with this computer. Now I can see WHY the computer is so infected.

Download gmer.zip: http://www.gmer.net/files.php
Unzip the file, and double click on gmer.exe, select Rootkit tab and click the Scan button.
When scan is completed, click Save button, and save the results as gmer.log
Warning ! Please, do not select the "Show all" checkbox during the scan.
Post the log to your next reply.