While Parallels is open and you have not yet started your guest OS Windows you can run Compress on the PVM file. The Compress option is in the menu bar options. That will shrink the PVM to the smallest workable size within Parallels. You don't lose files.
Also your Parallels OS is very large?
There are also ways to give more space in OS X. Google options on what you can move to trash in OS X. Also a fresh instal of Mountain Lion when it comes out will give you a clean system and theoretically more space as long as you don;t load it up with unwanted Apps.
Rebuilding the Parallels system will also give you a leaner Guest OS. My Win 7 PVM is 22GB and it has Win 7 Ultimate, Full Office Suite and Acro Pro. I don't store any files in it.
That's my two cents worth. Sorry if it is stuff you already know.
IP
Last edited: Jul 15, 2012