If you couldn't get in, how did you manage the bitdefender scan in the first place?
One thing you might try is removing the hard drive from your computer (if its a desktop?), hooking it up to another computer, and scanning it from there.
You can also try the UBCD (www.ubcd4win.com), boot your computer from the special CD you create, and run scans from it instead. It has helped me in the past a lot.
Cheers!
--The Comodore