Nvidia 8400gs 64bit + w2007 hp

I did a clean install of windows 7 64bit(professional) on my existing 32 bit vista premium, every thing went fine expect the monitor resolution. If open any videos using windows media player or real player or watch TV, it displays in a blur mode. Photoes can be seen clearly, only videos that i play are not clear. I dont know what went wrong. All i did is updated a new nvidia driver for my 8400gs. Please let me know if any thoughts on this.

Maybe you chose the wrong driver. I dunno, that's weird result.

You can rollback your driver to the previous version in device manager. Right click your 8400 under display adapters, choose properties, go to driver tab and click Roll Back Driver.