Vista 64bit not booting & crashing

[badRick]

Hello all

I built my latest PC about 4 months ago, and my OS is windows vista home premium 64 bit. about 50% of the time my PC will work just fine, it'll boot up nicely and there wont be any issues. about 40% of the time windows just wont load, and i'll get a nice black screen and will be prompted with "windows did not shut down properly last time ...." when i reboot my PC. the other 10% of the time windows will load, but crash for seemingly no reason and without warning after anywhere between a few seconds and a minute. I've put my system specs below:

Intel e8400 CPU @ 4050Mhz (9x450FSB), ca. 1.39 Vcore
6GB OCZ reaper PC8500 DDR2 @ 900Mhz
Asus Maximus Formula Mobo (DDR2 of course)
Thermaltake ToughPower 750W PSU
BFG 8800GTS (G92) at 760/1950/1125
and a 500gb seagate sata II HDD with 32mb cache

So thats pretty much it, i'm totally stuck on this one. I've tried everything i could come up with, updated drivers, updated windows, went back to stock clock speeds on CPU and GPU, but nothing. If anybody had any advice i'd really appreciate it, im getting sick of restarting my PC 10 times a day!

[Lsdmeasap]

Sounds to me like some bad RAM, or bad RAM timings/voltages

[badRick]

All RAM settings are on auto, the voltage is 2.1V on auto according to everest. Do you think it would be worthwhile setting the timings in the bios myself?

[Lsdmeasap]

Yes, AUTO is never a good idea. It is put there for those who do not know how to manually set things, and for setting up and getting a board going the first time. Auto usually is not best, and most times likely is too much or too little.

For 6GB you will for sure need +.1 -+.15 or so MCH voltage. And as for your subtimings, I can make only suggestions as I have never setup 6GB or you can ask the guys at OCZ for best subtimings for 6GB >>>
Asus Motherboards - OCZ Forum

If you want my suggestions if you dont get good answers there let me know