WIn7 suddenly filling up disk & stopping.

Sometime overnight, my Win7 VM started writing to the disk and filling it up...and then stopping. I can't seem to stop this behavior and have pretty much run out of things to remove from the drive to get more space (each time I try to restart the VM) so I can continue troubleshooting. Also cannot see the \\psf from either Win or MacOS. Host is MBPr with 128gb drive. Drive went from having something like 28gb free to nearly nothing. Suggestions? (This is somewhat urgent as it's my work machine...)

Parallels is build 8.0.18483
MacOS is build 10.8.4

 

Just as an update, I can no longer start the Windows instance to try and recover one key file. There is not enough drive available to install another VM per EN112469. Is there any other way to open the pvm file via the Mac to get to the files? The Parallels Mounter makes it accessible, but not at the file level.