I have a 7800GS AGP on my athlon 3000+ and its pretty quick, plays Oblivion ok at 1280x1024 and even Crysis quite well at 1024x768 with mostly high settings turned up.
I recommend these drivers:
http://downloads.guru3d.com/ForceWare-Omega-Driver-v216921-XP-download-1814.html
theres a thread about them on the Guru3D forums at:
http://forums.guru3d.com/showthread.php?t=248770
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Other than that I don't know. If its an AGP card make sure your AGP bus gets at least 64 mb of system ram avaliable to it in the bios. (Don't think this is the problem since you have been running Vista already).
It could just be that Vista is a lot more responsive than XP and your not used to how slow XP's UI is. Even the Vista RC1 that just expired on my system the other week is a lot snappier than XP. And thats with the original CR1 video drivers.
I recommend these drivers:
http://downloads.guru3d.com/ForceWare-Omega-Driver-v216921-XP-download-1814.html
theres a thread about them on the Guru3D forums at:
http://forums.guru3d.com/showthread.php?t=248770
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Other than that I don't know. If its an AGP card make sure your AGP bus gets at least 64 mb of system ram avaliable to it in the bios. (Don't think this is the problem since you have been running Vista already).
It could just be that Vista is a lot more responsive than XP and your not used to how slow XP's UI is. Even the Vista RC1 that just expired on my system the other week is a lot snappier than XP. And thats with the original CR1 video drivers.