Freezing Issue Manifested after upgraded video card

[Gatts]

I would try to reinstall Directx then the game only... after both DirectX and KB were reintalled and the crash continues - check your LOG (click right mouse button on "My Computer", LMB on "Manage" and read all what is stored in
Computer Management Local
-System Tools
--Event Viewer
--Performance Logs and Alerts
and of course focus on times of the game crashes, it may fasten the read process.... this may lead you to your question -> how to solve the lock up issue...

Hint: check if the new video card is really hard-pressed into the mobo slot, may sound stupid, but occurs quite often in such cases