Problems with Geforce 8600M GS 512MB

[M3MPHIS]

Hi all! I have laptop HP pavilion dv9690en(Intel core2duo 2.2, 2GB ddr2) with Nvidia geforce 8600M GS. The problem is that card is not working at max performance after i downgraded XP from Vista. Every game i try to play is running with lo FPS, even Ati mobility radeon HD2600 512MB is running faster. I tryed a lot of new drivers from this web, everything is working, but when i start (for e.g.) Medal of honor airborne (everything on max, 1024x768) it runs very bad. Even on vista this game was running faster. i think it is only because of video driver(the best for me was 171.23). Every time i start Nvidia control panel and system information there i see different frequency's of gpu, fsb cpu, Frequency's ar floating (for e.g FSP from 180Mhz to 500Mhz). I'm using notebook hardware control and always MAX performance in it, so what is happening? I installed Xp because games are running faster on it, so why my video card is not working faster on xp(even a bit slower)? I had laptop ASUS F3KA (AMD 64x2 2Ghz, 2GB ddr2) with Ati mobility radeon hd2600, when i installed XP games was running about 3 times faster than on Vista! Please help and sorry for my broken english :)