New Graphics Card causing stall


  • Yesterday I received an MSi nVidia GeForce GT640 graphics card to replace my aging EVGA nVidia GeForce 430 card. My EVGA card has no problems but when I switched the cards, my MSi card triggered AVG Watch Dog to run system checks and afterward would stall. So I tried to go into safe mode with the new card installed. It would go from start to Classpnp.sys and then stop. I left it to sit for atleast five minutes or so. But it wouldn't go any further. 

    What do I need to do to fix this problem..? I have Windows 7 Home Premium Edition. Would I need to use the classpnp.old? 

    Friday, December 14, 2012 6:32 PM


  • Did you uninstall the NVidia drivers before swapping cards?

    The normal procedure I'd recommend is:

    Have the latest NVidia driver installer on hand (downloaded from

    Uninstall the current drivers.

    Shut down. (Don't restart.) Turn off the power supply (or unplug the PC).

    Replace the graphics card.

    Power back on.

    Boot into Windows.

    Install the NVidia drivers.


    Hope this helps.

    Friday, December 14, 2012 9:58 PM