Virus?

Can someone here pls help me as I would like to do a test too see if I've been infected with the MFV as I think I have but not 100% certain until I can do a full test on this.

Is there anyway I can perform a test on my PC to see if I've been affected by this and if so how.

The reason why I'm asking this Q is because I encountered a weird HDD problem today. Well what happened was that I went to install Bitdefender V8.0 free edition to use as my second on demand scanner with NOD32, as NOD32 is my main real time scanner. Now when I installed BD 8.0 I got a msg saying that it cannot install because my HDD is full, now this totally strange because a few days ago when I checked my HDD is showed I had about 15+GB or so still available. Now there is no way that within 3 days or so my HDD all of a sudden has been filled with 15GB's of data. Now it tells me I've got about 60MB's available, which does not sound right at all.

My HDD is a Maxtor 30GB.

I am suggesting either the following:

A. The Windows MFV virus.
B. A virus (what ever it may be)
C. CMOS Batt, but my clock still keeps the time.