Alright I'll try that out, thank you

NOOB QUESTION HERE: When I leave my computer alone for a while it goes in hibernation mode I think. Just kinda dims lights, turns off monitor, but is still running. so i move the mouse around and my desktopback ground pops up, but nothin else does. no taskbar, if i hit ctrl+alt+del its goes to a black screen and I can see my mouse arrow still. I can right click, but nothing I click does anything. Now is there a button that I push that brings up a log-in screen at this point or is my windows 7 screwing up? i'm not sure

Alright I got a question to add to this. Dont know if that is forum rude(sorry if so) I got the crappy nvidia BFG 8400. I was gonna buy that nVidia 9500. its cheap and i heard its good. but my buddy says that its like a year and a half old. u can get something better for a little bit more. I wanna spend around $150. of course not top of the line, but that GTX 9800 looked nice. But then i was told, no nVidia is out, ATI is in now. Ihad a bad experience with ATI , he said that nVidia is not good rigt now and ATI is. is this true? Please help. around 150$, a brand new e-machine tower. what should I get?