BSOD too frequent

hi, my PC acts weird now. when i boot up my PC, on startup, programs randomly get crash.

at one time, the windows desktop manager crashed so i couldn't use aero theme. i restarted my PC and it's fine.

another time, the catalyst control center (AMD video card) crashed, i decided to manually restart the program.

another time, i couldn't play the witcher 2 (game), it crashed as soon as i loaded a saved game. i restarted the PC and i could play just fine (without crashing).

another time, AI suite II (from my asus mobo) crashed.

another time, a lot of random programs crashed without i know why...

i don't know what happens, when i restart or boot my PC, random program gets crash but another time the same program goes fine. but this happens alot and frequently.

i tried repairing windows, it seems now windows seven only have startup repair only (repair yada2 that prevent windows from starting).

oh, 2-3 times, i got bluescreen when playing game or working (with a lot of adobe prorgams at the same time), it said memory something. then i tested my RAM with memory diagnostic tool and chose extended test. it passed just fine.

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yesterday i decided to reinstall my windows (fresh install), this is not 24 hours yet and i already had 2 BSOD. i can't even do windows-update, always stuck at some point.

i attach 2 BSOD dumps, one is before the reinstall, one is today (24 hour after the fresh reinstall). my rig specs are updated and complete. my rig's age is only 3 months old except for the motherboard, i have that mobo RMAed 3 weeks ago.

please do help

oh one more thing, i feel like now my rig is performing under its normal performance. it loads everything slowly, everything that is still loading gets to "not responding" state before it's done, and sometimes the not-respondings don't respond at all (i force close them). and this happens on my newly reformated/reinstalled windows 7.