Can you get into safe mode?Rootkit Revealer
it may be worth running this on your PC. RootKitty
may also help especially as you have used BartPE. If you do have a rootkit then your going to have to nuke your PC and do a clean install. However if you can get a hijackthis log posted one of the experts there may be able to help you.
From BartPE which antivirus scanners did you run?
If you think you are infected submit a hijackthis log to the HJT Forum.How to submit a hijackthis logDownload Hijackthis
Try running the following from safe mode (Getting to safe-mode) Sysclean
you'll also need the virus template file from here lpt***.zip
remember to extract the contents of the zip file into the same folder as Sysclean.com
which is powered by the Kaspersky AV engine, you will need internet access to update it. If you haven't got net access in safe mode, update it before you use it.
If your good with the command line also try Sophos Command Line scanner
this command will scan all of your hdd's SAV32CLI.EXE -F -di -remove -dn -mbr -all -zip -p=avscanlog.txt and give you a log file to review afterwards.Also try installing and running A2 Free and Ewido
I'd also run Spybot(Spybot Tutorial)
and AdawareIf your using Win2K/XP run adaware/spybot from "safe mode with command prompt"
If your using Win9x just run it from safe mode the command line options aren't needed..At the C:\ prompt type the following:-
C:\progra~1\spybot~1\spybotsd.exe /autocheck /autofix