We made some changes in the Windows simulator in build 2585. Can you try that version and see if you are having problems with it? Build 2583 is the build before the change, so if 2585 is not working, does 2583 work?
Do any of the Corona samples fail to run correctly or is it only your own projects?
We have fully tested the released version of the Corona Simulator on all Windows OS (including Windows 7) and have not seen any problems nor have we had any users report any problems like this, so this may point to something in your system that is not working correctly.
-Tom