Hanging on "Running package scripts..."

Hi, I've just installed the latest update to Parallels 7 - can't tell you the version number at this point.

For the last 18hours I just see a prompt saying "Parallels Desktop is being installed" and the "Running package scripts" message. I can't cancel or restart.

I don't want to force a restart particularly. It's also stopping me from using and relaunching Finder

Any help would be appreciated
Thanks, Steve