Upgraded RAM to 4 gig ... only see 3.5?

Ok, I know that there are a ton of threads out there about this topic, trust me I’ve looked …

I just wanted to get answers from Kirupians though, because heck, I like you guys.

Anyways, I’m running an AMD 6000+ with 4 gig RAM and Vista Ultimate, but 32 bit not 64 … so obviously I know the problem with it not showing 4 gig but only 3.5 … my question(s) is this …

-Is Vista only using 3.5 of the 4 gigs?
-If it is only using 3.5 of the 4 - is there a way to make it so that it uses/shows that it is using all 4 gigs?
-I have Vista Ultimate 64 available to me as well, am I able to upgrade from 32 to 64 without complications … or will I have to do a clean install?

Thanks again!
Boon. :thumb: