Vista 64-bit/XP pro 64-bit/windows server 2003/2008 64-bit driver - I installed the Ralink rt73 driver (as it supports xp pro 64-bit); available from here(size is about 17mb). Then I replaced the rt73.inf file (back up first) in the folder 'Program Files(x86)/RALINK/RT7x Wireless LAN Card/Installer/WINX64' with my modified version; which is downloadable from the downloads section. Then you go to device manager and scan for hardware changes, and when asking for driver for belkin point to the previous mentioned 'RALINK/...' folder containing the modified inf file.
Another useful link is this - does my belkin f5d7050uk work with vista? .I tried this version of the Ralink updated driver for vista 32/64bit yesterday with my belkin usb adapter (uk version 3) under windows server 2008 64 bit and it wouldn't install, whereas my method worked both with Vista 64 bit and Windows Server 2008 64 bit.
If you are having problems downloading the large 17mbs file, then below is smaller files to download. Make sure all files are downloaded to the same folder, then run the batch script to restore the setup exe for the driver. All files need to be downloaded.