Hard Disk Space

I am writing in the hope that somebody could shed some light on an issue for me. I noticed I was missing 40 gig of hard disk space on the hard drive on my Macbook pro. I then found two folders in the My Documents folder. One is labelled Microsoft Windows Vista and it occupies 7.7 gig of space. The other is labelled Microsoft Windows Vista 1.pvm, and it occupies 33 gig on the hard drive. The only thing I use Parallels for is MSN messenger in order to communicate with my 12 year old daughter who lives in Sweden, as Mac does not support video MSN messenger. I have no video or pictures on the mac. I am thinking that there is no way Parallels/Vista should be taking up 40 gig. Can someone please show me how to rectify this issue? Or do I need to totally uninstall Parallels?

Thank you.

Henry.