Bad video playback quality since I switched from XP to Win7 x64

Hi, the title says it all: since I switched from Xp SP3 to Win7 Home x64, the video playback quality is quite bad. I changed the cpu (C2D E6750@2.66Ghz -> C2Q Q9650@3.0Ghz) and added 4GB of RAM for a total of 8, but my graphic card is still the same though (Asus EN8500GT) so I don't understand why the quality would decrease. Maybe it's because I used the integrated Windows 64bits drivers for Nvidia 8500GT instead of the Asus ones. But there are no 64bit drivers available on the Asus website. Anyway, on XP I used to watch my videos with MPC-HC, FFDshow, VSFilter, Haali Splitter and didn't tweak any settings. I installed the same softwares on my Win7 system (except for VSFilter I can't install) but my XviD or x264 videos look blocky and it's like some parts of the picture are "floating", it's not clean or smooth as it was. I don't know why the quality would change that much but if you've got an idea, please let me know! Thanks! EDIT: I also wanted to mention that I installed directx_feb2010_redist to have MPC-HC run on Win7 without displaying an error message.

(except for VSFilter I can't install) Why not? Also, what video renderer are you using? and is Aero enabled or disabled? try use haali's renderer or overlay. ..and I think it is best you install proper drivers for your graphics card if any are available.

@namaiki I don't know why I can't install VSFilter but the dll doesn't seem to register. As for the video render, I'm using either MPC, ffdshow or haali for h/x264 @Alante Thanks, I 'm downloading those drivers. The purpose of my system is geared towards audio as I'm a composer and audio softwares are real CPU and RAM hogs. I don't know what would be the benefit to upgrade my GC as I don't need something very powerfull to display audio signals. And what I really like about this GC is that it's got a passive cooling system, so it's silent :) @chuuey I don't know what you're talking about.

I see, then you're right - that should be enough and of course a silent card is best option. :) I'm not an audio producer or something like that, yet even I aim for silence (silenced my HD 4850 with passive cooling, a huge pipe based CPU cooler and most of my fans or Noctua)... It's true I almost got infected with an audiophile virus, but I managed to stop before it was to late. :)