[unruhly]

Is there any additional information about the error in the system logs?
Let us know if you don't know how to find them.

Next step after your re-install didn't fix it is to check what programs are running and shut down everything possible. There's something running that's got a lock on the memory that the game needs to run. (my guess)
Do a fresh boot, bring up task manager and make a note of the amount of memory in use. On a fairly clean system it should be no more than about 125mb. Under 100 meg is great.
Go to Sysinternals.com, then click on System Information and download PROCESS EXPLORER. This will help you find things that are running that you never knew existed.

I've got a lot more things we can check so don't give up yet. It just may take a little time with having to go back and forth. The best thing you can do is to provide as much information as possible.