[OT] Computer Virus Trouble Follow-Up

Re: My recent do-it-yourself virus repair questions...

I took the advice given by a number of folks here and got a USB hard-drive enclosure, took the ailing HDD out, popped it into the USB enclosure, hooked 'er up to a computer with fully up-to-date AV software, scanned it, and... it found nothing. I configured the AV to scan everything, down to 6 levels of file compression, and including spyware and other malware. Nothing.

Well.. what the hell, I went ahead and copied all my data files to CDs -- no important data had been lost. Scanned the host computer when I was all done, and still no signs of bad stuff going on. Host computer is showing no ill effects -- so far.

Now, I have gotten false alarms from AV software before, but that's all they were - false alarms, with no apparent harm done to the computer. This episode definitely had a bad effect on my computer -- it wiped out e-mail accounts, and wiped out the WinXP user accounts. The computer wouldn't boot up. It looks like it's for real, but it can't be found anywhere.

I used the same AV software to scan the HDD on the new host computer, so if the bad stuff was still in there, it should have spotted it -- after all, it did warn me of it the first time, it just said it couldn't do anything about it. I suspect that this is a rootkit of some sort.

I still will format the HDD and reinstall the OS and all the other tedious, time-consuming BS that goes with this process, but -- what are the odds that the data files will re-infect the new install? The files are all .mp3, .wav, .wma, .jpg, .doc (MS Word), .wpd (Word Perfect), no executables. How much risk am I taking?

Can anyone recommend software to detect and remove rootkit infections?

Thanks again, as always.