GW Start up problems, help please!

ok, so i bought a barebones kit about a year ago, worked fine until it started to freeze while playing guild wars. i figured no biggie, it was a celeron proccessor, its said to run really hot, i got a new P4 2.8. That one....didnt work. froze 30 seconds after start up and then celeron did the same after i put in my P4. then my dad went all-out and got me a new MoBo. didnt start until we realized we didnt connect the adapter to plug in the power, started up, works great now. until yesterday when it froze, but it was a one time thing...then today the screen's color got all messed up and started to switch to a black screen and normal, then froze again. hasn't frozen since but theres still a problem. this is my main concern: I CAN'T PLAY ANY GAME! i re-installed my driver for my video card, direct x 9.0 again, still nothing. when i start Guild Wars it downloads updates, starts up and goes into black screen, and then just stops there. guild wars mouse skin is set and i can move it around, but it doesnt get out of the black screen, cant ctrl+alt+delete or esc for it. i also tried to run Wolfenstein: Enemy Territory, pretty much same problem, except the start up screen for that is gray...if any one can help me a little bit and took the time to read all this, thank you!

hate to bump but i also want to add that i'm going to be reformating the hard drive and reinstalling windows, any other ideas though?

Whats the rest of the spec's of the PC, what your describing sounds to be an overheating problem with the graphics card(if you have a card, and not on-board), whenever you change processor or/and motherboard, you really need to reformat and reinstall windows, regardless of what other people may say. Your current windows installation only recognises what was originally in, so the new parts will be alien to it, and that hopefully will be your problem.

Give an xp reinstall a try first, reformat your hard drive though.

lol yep, just reinstalled windows, reformatted my hard drive, works great but yea, i have an Nvidia GeForce 5600 video card...no onboard crap, and it does run cool, idles about 15*C, maxs at about 25-30..which i think is pretty good lol