XP or Vista

[zanthor]

I am currently using XP with..

AMD 2.6 Dual Core
GeForce 9600GT
4 Gigs of RAM

I don't have to much lag issues currently running 4 WoW clients on one machine. My problem is that XP can only ever use 3.4 gigs of the 4. IS it worth me switching to Vista to use the full 4 or will Vista eat up so much more resources id actually be losing?

Since you shouldn't be using over 3gb of ram to run 5 copies of WoW you wouldn't see any benefit from switching to a 64 bit OS.