computer freezing problems

[recklessfire13]

My computers been freezing ever since installed a new motherboard, processor, and hard drive last week.
It ran smooth the first couple days, but now it freezes up during games and my graphics card software shuts down and i go into software mode. Also when i exit my games my desktop returns to its default brightness. PLZ HELP

i have Window XP Professional w/ SP2
          Maxtor 80gb hd
          ATI Raedon 9200 SE
          Gigabyte 512mb ram
          Athlon 64 3000+ at 2.0ghz
          PcChips M870 Motherboard

[Flame]

Have you made any changes since it was working fine? Are all of your drivers installed properly? Are they the most updated?

Flame

[GX1_Man]

Does this help?

http://www.computerhope.com/cgi-bin/yabb/YaBB.cgi?num=1133458168