I'd still prefer Win7 64 bit if I had a choice.
Although BiaB is 32 bit, the rest of the system can still benefit from the 64 bit OS.
Anything over 4 gig may be 'wasted space' for a 32 bit app, but everything else that is running at the same time may benefit. Just my opinion.

In your case upgrading from 2 to 4 gig of RAM would be the first step I'd try. Likely make the biggest difference on the current system. It'll be recognized and used, and doubles your current RAM.
However the investment will not carry forward to your next system due to DDR2 vs DDR3 (or 4). DDR2 is on its way out.

However, IMO your best bang for buck would be the additional RAM .. for now. Depends a lot on how long you hope the current system continues to serve you.


Make your sound your own!
.. I do not work here, but the benefits are still awesome