I was running all previous versions of VirtualBox on my Win7 x64 system without any problems. Every upgrade went smoothly, until I tried to upgrade to 4.04 (I can't remember what version I had on the machine previously). At the moment, it is just stuck on the step after it disables network drivers and says it "could take several minutes". Well, I waited over an hour and it still hasn't finished. Cancelling doesn't do anything, so I had to kill the process to get out of the installation.
Does anyone have advice on how to "clean" my system so that I can get VirtualBox running again?