stick with xp pro. Its supported with security patches for the same amount of time as vista business is (longer than mce, home, vista home and vista ultimate)

oh didn't knew that,hell it makes my relentless quest to make a fully up to date xp installation cd worth da wait

hmmm...you tell me now...

4gb will definitely help in performance, as less lag, faster boot times, etc will be noticed. The games will load a bit faster, and it will future proof your system a bit. Many new games coming out soon will utilize the extra ram, and with the extra ram, you will be able to multi task flawlessly. Just remember that with a 32bit OS, only 2.4-3.5gb will be recognized by your system, so to save money, I'd Suggest going with 3gb instead of 4. It all comes down to how much cash your willing to spend. If you really want to speed up the loading times of your games, consider getting a 10,000rpm hard drive.

agreed!!!

4gb ram is pretty cheap now though, i can get 4gb of ddr2 533 for well under £50

that's right, and I've even seen lower!!