Freeze problem with new GPU...msi gtx560ti hawk

Hey guys Recently i have upgraded my GPU from gtx460 to MSI gtx560 ti hawk and after installing this card..whenever i play any games within half an hour the screen freezes for about 15 to 20 seconds and the screen goes black and then return to normal gameplay..

i Don't know what the problem is i have updated my GPU (280.26)and sound driver to latest and some essential updates..
and before installing this new card i make sure to uninstall all the previous drivers of nvidia and after that run driver sweeper to ensure full GPU driver removal..

and my GPU is not yet oc'ed it is running on factory oc'ed

My system specs are:
Windows 7 ultimate 32bit sp1
Intel i7 2600k
Asus P8P67 pro
Msi gtx560 ti hawk
Corsair vengeance ddr3 1600 4gb
Benq 3d led monitor 24"
full tower Zebronics invader atx with 6 fans
Corsair hx 850 PSU :confused2:

Hello there, navin00!

Well, to tell you the truth, I don't like running DriverSweeper to clean driver leftovers, I don't remember who told me that, but I began to take his advice.

Can you take a ScreenShot with GPU-Z to check that everything is alright?

When i upgraded my GPU (about 2 weeks ago), the card wasn't properly seated on the PCIe port (even though i thought it was) and the GPU-Z reported it as PCIe x1 instead of PCIe x16 (and man, it was different)

Thanks for reply the gup is docked well and to confirm i redocked the gpu here are the screenshots...

Weird, everything seems alright!

Can you tell me, when does this locking thing happens? only when heavy gaming? or anytime?

anytime while playing games...