I just recently bought a Gateway MT6841 and it was running perfectly fine when I played WoW (World of Warcraft) and then it stopped charging so I sent it in and had it fixed and I just got it back and it lags horribly. I went to check my system information and it says I have 501.56 RAM I was wondering if this is even possible and if so why did my computer all of a sudden go from 512 to 501.56? It's an Intel Duo Core Porcessor 2.0 Ghz with Windows Vista. I am also wondering if I buy more RAM would my proformance increase? Thanks for the help.