Windows 7 - Freeze when playing games

When I'm playing games, windows starts to freeze.
So I'm unable to move my cursor, the sound starts to repeat every split-second.

I've checked my temperatures, but they're all stable at around 50-55°C.
My graphics card is up-to-date with the latest Win 7 drivers, provided by nvidia.

After a hard reboot, nothing shows up in my events log.

Hi and welcome to sevenforums. I wondered if your running out of ram and starting to use pagefile. could you have task manager running while you ar playing and see if your ram goes down to almost nothing availible?

Let us know how its going

Ken

I have a monitor running on my keyboard (it has an lcd) and the max I can get is 75%.

What games are you trying to play?
Are these games online or just single player?
I myself had a blackscreen problem with Half-Life it would do this until I gave hl.exe access threw the firewall.
I would see if the games are trying to call out threw the firewall and windows is asking if this is ok. You can check to see if the game has access threw the firewall in control panel.
Also what level is UAC on? If its set to the highest settings some games might have an issue with it. Set it to default of one lower than default and see how that works.

I've had it with the games from bigfishgames, and with anno 1404, didn't try anything else yet. All of them are single player.
So, no firewall problem.
UAC is turned off.

I've also changed my virusscanner to avast! from nod32