well, 32 bit OS can only handle 3.5 gb of ram, so you should be fine either way, 3.5 gb is plenty for fb games and youtube. there are 2 versions on the dell latitude E6400: 1 with a nice integrated gpu, and 1 with a crap one. i would download speedfan, and go to the info tab and see if it reads you a gpu temp. if it does, you have a nice gpu, but it will get to 90-100c during game usage. if there isnt a gpu temp, you probly have the other version, which should still be fine for fb games and youtube. so, if you have the nice gpu, you can try replacing the thermal compound, its really easy: take the battery out, unskrew the skrews on the back panel, take off the panel, unskrew and remove the heatsink over the cpu, and if the thermal compound is white or is dry, replace it with new, quality thermal compound, such as arctic silver 5 or better. if you dont have the nice gpu, then your best bet is to make sure you are running on high preformance and dont have a lot of stuff in the background. you can check by opening the task manager by pressing control shift esc. then go to processes and end any that you dont want running. there will be a lot that you dont recognize, so look at what the description is. you shouldnt have more than 40-50 usually. hope this helps!