hello eveyone this is my first post Hopefully you guys can help me solve my issues. A friend put together a new system

antec neopower 500w
gygabyte p35c-ds3r rev 2.0 -mb
Intel Core 2 Quad Processor Q9450 2.66GHz 1333MHz 12MB LGA775 -cpu
OCZ Reaper HPC 4GB 240-Pin DDR3 SDRAM DDR3 1333 -ram
WD7500AAKS 750GB 7200 RPM 16MB Cache SATA 3.0Gb/s -Hard Drive
EVGA GeForce 9600 GT 1GB GDDR3 PCI-E 2.0 -video card
LG Super Multi Blu-ray Burner & HD DVD-ROM Drive Black SATA GGW-H20L
The Lite-On 20X Super Allwrite IDE drive
running windows xp 64bit

He built the computer and was having problems with the system locking up, so he brought it over here to me. Its kinda weird because i haven't really dealt with too much of the 64bit. He figured the lock ups were vista ultimate so he purchased windows xp 64, and had me install it.

Anyways, the problems come when I tried to install programs and run games, otherwise it runs ok with a random locks every once and a while. For example he wanted me to install nero 8 which he bought, and everytime i get to the point where the program starts to install past the serial and all that, the computer totally freezes cant even crtl+alt+del it! must shut it off and turn it back on. Same thing with all games starts to run, then total freeze.

I was thinking it might be the video card, so i updated to the newest drivers and still had the same issue, so to test it, I put in a nvidia 7300, and still get the same problem. Next thing i did was update the rev of the bios on the motherboard, didn't help. pulled the powersupply out to make sure plenty of power was going to everything and it should work fine. updated the firmware on all the drives. ran memtest on it for several hours and no errors, so its not the ram. with all of these problems worked through, kinda running out of ideas here. Its a really just installed not much on there but the system! what do you think i should do next? already spent way too much time on this and am getting very frustrated

What security and firewalls are installed?
Does it boot in SAFE MODE, even if the screen is a diminished low resolution screen?

re: safe mode

yes it boots in safe mode although i cannot run the operations in safe mode the are likely to lock the system up. there is not firewall running widows firewall is there but not enabled and antivir was running but i unistalled it just in case it was that had no effect

well i removed one of the 2gb dimms for testing and now it seems to run stable. I installed the nero program, ran a game without any kind of locks. check the manufacturers website and the memory is not on there for ceritified dimms but they dont even have any quick memory modules that are 2gb, only 1gb do you think i should hold onto what i have and wait for updates running the one dimm or return it and get a couple 1gb dimms

Mixing dimms (different sizes or different manufacturers) can sometimes mean nothing but trouble (like lockups as you find). I would recommend patience until you get an exact replacement for the faulty strip. I tell you now, 4Gb on XP is just window-dressing and you are very unlikely to see any difference from 2Gb to 4Gb.

solved

there was enough voltage going to the dimms the motherboard defaults were about 1.5v cranked it up to the manufatures highest recommended level and it works fine thanks for help

Good reliable memory at www.directron.com, www.zipzoomfly.com, www.outpost.com. www.newegg.com, www.kahlon.com, and my favorite best is www.crucial.com when they have it.