After my Radeon 9800 pro started locking up my display while being taxed under Windows XP Pro x64 edition, I thought I'd try swapping it out with one of the older cards I had laying around, the GF2 MX or my trusty old GF2 Ti. A quick search brought up this site reccomending a couple of the older XP64 forceware sets from Nvidia, and listing them both as supported cards with these drivers.
Wrong.
First thing you get after installing either of these cards under XP64 is "standard VGA adapter" which has no vid accel whatsoever, makes it about as usable as Win95 on a Pentium-90 Very slow indeed and no good resolutions available.
After about 3 days of hunting and several emails to various graphics card companies (Nvidia won't actually allow you to contact them direct, they refer you back to your card manufacturer) I have concluded that there are NO geforce 2 MX or Ti or indeed any sort of GF2 drivers available for 64 bit Windows, despite being included in the very latest 32bit driver packs. The oldest card supported under x64 appears to be the GF3 which you can install from version 66.96, anything later than that and it's GF4 and upwards only.
As such I'd reccomend anyone with an older nvidia card sticks with 32bit for now...