Motherboards & Memory

You guys are a WEALTH of info,and I appreciate all i've read in these forums,however i'm still not much good w/much troubleshooting. I've had this sytem (friend built) for a couple of months and it runs great(windows,email,internet and apps)except it crashes within minutes whenever any fairly recent(2yrs old)games are played.Most software techs tell me it's probobly a mobo/mem related issue but at this point i'm at a loss on what it could be.I ran the mem in slots 1&3,and then 2&4.Works for a while the i swap them back and works for a bit but games still crash.Friend cant find any problems and i ran win memtest w/out any problems found.My system is a: Intell-e8400 ga-ep35c-ds3r mobo G-skill 2*2gb 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel gforce 8600 vid 600w thermaltake ps blue ord fan. It's been good for a week now but cod4 is still a prob plus i'm not sure how long it will last.Is it possible a voltage issue in the bios and if it is could someone walk me through any possible changes or a possible mobo or mem defect.Any of u guys help would be greatly appreciated.Thanks in advance. Anthony.

Some motherboards just dont like ram over 1.8-1.9 volts. Im to lazy to look into it for you.

I have fixed systems in the past by lowering the speed and lowering the voltage.

Yesterday my friend had DDR2 1200 ram his mobo supports the speed, but the ram he got was 2.2 and it wasnt stable at all. I got him to bring the ram down to 950 @ 1.9v and it is 100% stable a 4.5 on his e8400.