There are so many reasons why this could happen, sometimes its caused by
background programs, possible suspects include: spyware, virus', intrusive
virus checkers (including Norton).
As there are so many reasons why this could happen, a good idea would be to
start windows with all 3rd party applications disabled and then try playing a
game. If it doesn't minimise then you know its a 3rd party program that loads
up in the background.
To disable 3rd party programs which arn't needed for normal operation of
Vista try this:
1. press 'windows key+r' to bring up the system configuration application.
2. Then click on the 'selective startup' selection and ensure they are all
checked except 'load startup iteams'
3. click the 'services' tab and then 'hide all microsoft services' then
click 'disable all'.
4. Restart and see if the problem still happens.
5. If it (hopefully) goes away, look though your startup/services and check
the ones that you would like to keep running and that you think arn't causing
the problem.
This is a safe procedure and you can undo your changes at any time by
changing it back to 'Normal Startup' at the 'General' Tab of the 'System
Configuration' application.
Good luck, hope it helps.
Also, just as a long shot, try updating your graphics driver and running
Windows Update.
