last night I experienced what I think are symptoms of virus when I was running Windows XP on Tiger (installed through Boot Camp.) But I'm not quite sure if it is indeed virus, if so then what kind, or it is just a spyware that can be dealt with without formatting. This whole thing started after I downloaded some software from unreliable sources (yes, shame...)

What I've experienced so far is:

- Pop-ups of "Windows cannot find RECYCLER\..." Autorun-eater also reported some suspicious files but after running Norton Antivirus it stopped.

- Constant freezing. I tried to back some of the stuff to my external hard drive but it always froze. Going to task manager and restarting explorer.exe did not bring back the task bar.

- For about 5 times, the Windows reported that it could not start up properly. When I chose "use the last known good setting," it only worked sometimes. In other cases, the blue bars scrolling in the middle stopped abruptly and there was a brief moment of a blue screen and it went back to startup only to repeat the same procedure. Safe-mode did not work.

- I was using Norton Antivirus 2009 but did not detect anything serious; nor did it fix the problem. I tried to install Internet Security 2009 but since the windows keeps on freezing, the installation was not completed. I also ran a series of respectable spyware-removing softwares but did not fix the problem either.

My concern now is the potential problem of formatting the windows. I've got the windows installed through BestBuy so I myself don't exactly know how. I have read some threads here regarding the matter but would you recommend that I do it myself or go to a technician for it? I do have some basic knowledge of both Mac and Windows but as you can see here, is not sufficient. Personally I'd rather do it myself. I'm only worried that I might make this problem bigger.

Also, since my external hard drive was connected at the time when problems began to emerge, I think it may be infected too. I have another computer set in Windows only but I'm afraid the virus (if it exists) may spread. Should I risk it and run a scan on another computer or abandon all hope and give the whole thing up? I think I can save some of those through burning a disc in mac OS but wouldn't it be all the same?

So just to recap my questions:

1) Do the symptoms above suggest genuine virus infection?
2) Should I try to work my way around it or format the windows portion of the hard drive? (I have the mac-windows drivers.)
3) Should I format it myself or consult a professional?
4) Should I risk testing my external hard driver for virus in another computer?

Sorry about the lengthy inquiry. My essays & exams are due very soon and I am having a bit of a breakdown. Thank god I saved those files in mac OS.

I do ask advice as detailed as possible but if you can just point me to the right direction by posting helpful links, it would be very much appreciated as well.

If you need to see any more tech. details just let me know. I may have to ask you where to look for them, however.