Can't login to XP following AVG healing

I have read the rules, but I cannot follow any steps as I cannot even log into XP. I apologize for this.

Here is the description of my problem.

I stupidly got a virus (my own fault) from a P2P network called DC++ (fantastic program, btw). I recognized its presence immediately, as it created a folder called "msview" in my system32 directory full of bogus "keygens" and "cracks", and modified my DC++ settings so this was the only folder I was sharing. It also created a file called magnet.exe in my DC++ directory. I tried manually deleting all the bad files and registry entries I could find, but they kept coming back.

At this time, my entire O/S ran fine, only DC++ was affected.

On a friend's advice, I downloaded Norton AVG Free and ran it. It immediately detected a "PSW Banker" trojan horse and a "Tibick.E" worm. It automatically "healed" them and prompted me for a reboot. Upon reboot, XP did an interesting little dance where it logs me in for about 2 seconds, then logs me back out, then repeats the cycle infinitely. Reboot again, same results - stuck at the "login shuffle". Safe mode - same result.

At some point in all my reboots, my HDD became unrecognizable as a boot device, and then completely. I was toying with BIOS settings for some reason and honestly can't say if this was before or after the HDD recognition issues. I managed to get the hard drive recognized again, booted Windows to "last known settings that worked", got into Windows, and repeated the whole process again (healed virus with AVG, to infinite login/logout shuffle). This time, even if I choose "boot to last known working configuration", I still can't get into the O/S.

There is an AVG forum for support, but you can only get a login account from inside your AVG software. Great, I cannot USE my AVG software (or my O/S). And I'm on a work PC now where I do not have admin right and am sure I cannot install AVG. I really wish I could get this issue posted in their forums... I searched and it's not there.

Any ideas? Thanks in advance for any assistance. I am on the verge of re-formatting but that would be a huge task. My data is all backed up in safe places, but I have a LOT of software and settings that would need to be re-configured.

 

The root cause of me being infected, was my manually, intentionally executing a file of unknown (questionable even) reliability. Laziness. DC++ will not infect your PC on its own. I could have downloaded that exe from the web, through an email, or in an number of various ways. I stand by my statement that DC++ is a great network, with a great community. I don't go near Kazaa and the likes.

FWIW, I formatted my system and run AVG 24/7 now. At the time I infected myself, I had NO anti-virus software running... which would have stopped me from running the file in the first place. I've been using DC++ for several years, running every questionable exe I find that purports to be what I need, and doing other STUPIDER things for nearly a decade and gotten away with it, never had one virus (or at least one with noticeable effects). Always said once I got one, I would start using anti-virus software. ;-)