Well, for this may be several things. First off go to your help for windows, F1 key and type in DEP at the search it should have a listing on how to change the DEP settings. Try to turn it off and do what it suggests. Restart your computer.
Run EVERYTHING as Administrator. Make it so all programs are using the Admin and each .exe program can be done this way also.
If you can go to win7 w/sp1 it would be better, hopefully.
That is as far as I can stretch my mind thru the internet for help.
