Panda also has an online scan
http://www.pandasecurity.com/activescan/index/?track=1 we use this software for work and the pay for version is solid. It is also easy to un install if you are having problems with certain apps.
I use avg on Lynns pc and have it scan mine too via the network at home. Their free version is pretty good but the paid version is really good.
http://free.avg.com/us-en/homepage Like Liz said for me if it takes over 2 hours to fix then all files will be dumped to second drive and the system will be purged and rebuilt. My process for this is to copy all data files, downloads, programs that are hard to refind, most games are stand alone with minimal register keys so you can copy your whole WOW folder over without having to reinstall.
Next step after you have got all your files you want to keep copied over is to unplug that back up drive and reformat and start all over on your system drive. Get your OS up and running, all updates current and anti virus malware software loaded and updated. Complete scan of new install. Most good software now has a realtime protection so when you are ready to bring that second drive back up with all your files if it is infected the software should catch it before it can reinfect your OS. It is alot of work and can be a real pain. Sorry for you having to go through this. I just did this for Lynn on her laptop a while back and it took me several days to get everything back up and running.