alt tab cause application has stopped working error

When i alt tab, it quite often pop out this error: application has stopped working, in multiple games.
No idea what is cause of that.
I didn't install, or change anything lately.
I am using Windows 7 64 bit.
And it is bugged i can't click button for terminating application, i need pres alt tab, select this error window and click ok or something twice.
I have in event viewer error id 1000, supposedly it is cause by faulty dns.
But if i got this error in offline singleplayer game, doesn't make sense to me.

Bump

Hi Jeppe,
Suggest you run sfc /scannow.
report the results.

Roy

Have you try to change the keyboard to check if it exist.
If not exist, then the problem lies with the keyboard.

Eric3742 said:

Have you try to change the keyboard to check if it exist.
If not exist, then the problem lies with the keyboard.

How would keyboard cause, that application has stopped working and error 1000.
It just sends keystrokes to usb and it does work, or not.
Correct me if i am wrong, but i am like 99% sure, that keyboard can't cause this.

Hi Jeppe,
can you also run this tool copy/paste the output.
http://go.microsoft.com/fwlink/?LinkID=52012

Cbs log is reporting an OOBE hash mismatch, where did you get your install media, it looks corrupt

Roy