Vista forcing game into windowed mode

[Ryland]

I am having a weird issue with my home desktop (the one in my sig) where it sometimes forces a 3d game into windowed mode which is ok for some games but not Halo (which my son has started playing). What happens is that I double click the shortcut, it starts off in fullscreen then about 5 seconds into what is shown during launching it sends the game to the task bar (since Halo can't play in anything but fullscreen). Clicking on it in the taskbar reshows the window in fullscreen for about a second and then it goes back to the taskbar. So far I have:

* Tested the memory via memtest, it passed
* Used Furmark to test the video card for an hour, no problems detected
* Did a clean install (using driversweeper of the 260.99 drivers)
* Ran dxwebsetup.exe to reinstall DirectX
* Tried making the taskbar autohide

I can't think of anything else to try to fix this.

 

[ViRGE]

This is a long shot, but is it the Windows firewall throwing a fit?

 

[Ryland]

I have the firewall turned off because the computer is sitting behind a router. I don't see any messages popup. One thing I should probably try when it starts happening is to kill all other processes one at a time to see if a specific one is causing this.

 

[lxskllr]

It sounds like something's stealing focus. Have you tried disabling your A/V?

 

[Ryland]

It sounds like something's stealing focus. Have you tried disabling your A/V?

No, never even gave that one a thought. Guess its something else I will have to try once I get this occurring again.