That one can sometimes be produced by LSP troubles. So, just in case, try the following document:
(If there's a SpeedBit LSP showing up in Autoruns, it's usually best to just uninstall your SpeedBit Video Accelerator.)
One issue I just ran into as I'm trying to update to Mountain Lion but still want to be able to use Parallels (& currently have Parallels 5 which is incompatible).
I realized that I hadn't updated Windows 7 for apparently over a year so ran those updates. & Windows is weird since it looks like it is updated, but may still need to be shut down & then restarted a few more times to get it all installed. I had some issues when I thought it was updated but it wasn't all installed.
so don't know if this applies, but you might check if Windows 7 is up to date & of course that Microsoft Security Essentials (or whatever you are using for anti-virus) is up to date. & run a scan of Windows to check for viruses.
& of course the other big thing to try 1st when you have things that don't work. Shut down & leave the computer off for a few minutes to clear out any garbage in the volatile memory. That can often fix weird behavior & I would say to always start w the most simple thing 1st & then if this doesn't work, then go to the more sophisticated steps.