MrsGorilla said:
This site talks about Vista's 64-bit support.
Quote from this site :
Additionally, Windows Vista x64 versions require that all drivers be digitally signed by the developer. If you've ever installed a driver in Windows XP, you'll likely be familiar with the unsigned driver dialog, which offers a "Continue Anyway" option when a setup application attempts to load an unsigned driver . In the x64 versions of Windows Vista, this will not be possible. Microsoft says that it is requiring signed drivers so that it can ensure that drivers are of the highest possible quality; poorly-written drivers are, today, still the leading causes of blue screens and other system instability issues.
Unquote.
I'm not sure if this really is an advantage.
For instance if you want to install a somewhat different soundcard or anything, Windows may not accept the (newest) driver for that utility, which means that with a 64 version, one can only install the soundcard that windows will accept, rather than those that the user wants to use.