Games Minimize Upon Completing a Loading Screen

I Have a problem with running game clients. Every time a load completes in the game screen, it will minimize the client. It only happens if I am running the games in fullscreen mode, rather than windowed mode. Have tried a few things but can't seem to resolve the problem. It's been suggested to me to update driver, checked driver version, was up to date, updated anyways, still the same, tried tweaking firewall although this happens both with local and online games. Does anyone have any idea why this happens? I can't make all the games I play run in windowed mode, so it's kind of irritating.

COD 5 does it everytime for me mate , just as it loads , it minimises and i have to restore it , Crysis used to do it too , never managed to figure out why and i tried hard , i just live with it now.