ram or mobo problem???

[Possum]

My brand new comp has been restarting for no reason at all, after about 30 min or if i run doom 3 for 10mintues or so times so i thought a little extra cooling might help but its not overheating because in the process of putting in my new fan i noticed my ram was in slot 3. I put it in slot 1 and then it was restarting whenever i got into windows. So i switch it back to slot 3 and its working like it was before. I haven't tried slot 2 yet. My mobo only supports up to 400mhz pc 3200 and this is a 3500 but it automatically clocks it down. If i got a regular pc 3200 would everything work properly or do you think my motherboard is defective.
heres what i have in case that helps:
K8N Neo Platinum mobo
Kingston HyperX Pc3500 512mb
amd 64 3200
radeon 9800pro 128mb
no overclocking at all ive updated the bios and drivers

 

[ailevation]

What kind of power supply?

 

[DiSTuRbEd]

Get memtest86 and test it, sounds like your memory has some errors. :x

 

[Possum]

480 watt antec true blue

 

[psyno]

Memtest86 linkage. Great program. What temps are you seeing? Also, turn off the autorestarts when Win XP encounters an error. I don't remember how off the top of my head but i'm sure someone does.

 

[Possum]

as i don't have a floppy drive I can't boot off a floppy, and i don't understand how to install/burn it onto a cd because it will only let me instal on drive a or b which i don't have either. My temps are 29 system and 39cpu currently celcius. Thanks for the help so far by the way iam pretty noob at all this

 

[psyno]

You have a CD burner though? Download Memtest86 v3.1a ISO image (zip) and extract the ISO. Use your favorite CD creation utility to burn a disk from the disk image.

 

[Possum]

thanks a bunch going to run memtest in a min.

 

[Asus]

It wouldn't run at all if it was set to 220. Actually it would probably blow his PSU right away.