Lately my Boot Camp based Windows instance had slowed down to a crawl. Booting it would take a few minutes and everything after I had logged in was just as painstakingly slow. So, after a few minutes of searching I ended up on this suggestion. Guess what? That brought things back to life. Boot up time went back to the more expected quicker time and programs started responding.
So, delete the VMware Fusion folder in ~/Library/Application Support/ while VMware is not running, restart VMware, let it create Boot Camp related setup and boot windows. You are good to go!