Do you have a laptop or a PC?

i have a pc its a hp my mobo is a asus A7VBX-LA Socket A (462) AMD Motherboard w/Sound, Video, Lan with a amd athlon 3100+ 2.20 Ghz 236 mb, with 512 mb pc2700 ddr - sdram memory. my mobo has 2 memory slots i didnt know if the slots are ordered like primary and secondary so when i installed the new 1gb i put it in the original 512mb slot

I also have an Asus mobo and know that they are very fussy when it comes to ram. You should be able to download the manual from Asus and see exactly what is does support.

Hello,

Have you tried each module individually?

Have you tried alternating the slots used?

I would always suggest installing memory in matched pairs. 512mb and a 1gb stick sounds like asking for issues

im thinking that it might be the new card i took out my 512 and just ran the gig it still had the same problem just not as often

If its DDR hasnt it got to be installed in pairs of matching size and speed?

Try running MemTest86 to identify if the RAM is faulty. There is a livecd you can download.

In my 3 decades of RAM experiences, other than defective RAM and too much RAM for the BIOS or OS to access, the number one problem is mismatched RAM speed (measured in time such as nanoseconds or speed such as gigahertz). Be it slow or fast, all RAM banks must be the same. It generally doesn't hurt if it is also all the same manufacturer but that is only for swapping and power considerations. The chips themselves have the ratings written on them.

Not strictly true. Ive got a mix of PC133 and PC100 RAM (Not DDR) in an old machine and it runs just fine for the last 7+ years. One is 256mb and the other is 128mb.