RAM questions

Hi guys, hope you could help me with some RAM trouble i'm having.

My friend has a PII 300 Mhz computer that was purchased at compUSA. It had a 64mb stick in it, and two empty slots. So i go down to Frys (i know, i'm sorry), and picked up two 128mb of PC100 RAM. Popped them in the computer, and all it does is beep like 6 times, and nothing else. I tried just 1 of the 128mb sticks, same thing. So i was thinking that the mobo couldn't handle more than a 64mb stick. Ok, go back to Frys, exchange the two 128mb of PC100, for two 64mb sticks of PC100. Pop those in, this time, no beeping, but it won't boot. The original 128mb sticks i bought were generic, but the 64mb sticks i tried were name brand. So now i am at loss for ideas. i have no clue what kind of mobo it is or anything, even if i did, it'd be tough to find the specs as this thing is 4 years old.

Anyone know what could be up?

Did you try removing the original Ram? There might be a compatibilty issue between them. Or it could be an issue of the speed of the Ram. Try getting into the BIOS.

Usually when a system won't boot in this situation is because the RAM is not compatable with the motherboard. I would suggest that the RAM you require may be PC 66. This number is determined by the front side bus speed of your motherboard.

EDIT: As stated in the posts below that usually higher speed RAM should work at lower speeds. Sometimes it may not be the case, it depends on the BIOS, the age and capabilities of the MoBo and the type of RAM...I worked on a baby ATX last summer. It had FSB of 100 MHz and it simply would not boot with PC 133 RAM installed. It fired up and ran just fine with PC 100 however (same brand of RAM).

I *thought* that higher generally worked in lower applications... that is I know PC133 worked fine in my paren't 100 speed Duron.

Anyhow - find the manufacturer of the BIOS on the board (Award, American Megatrends, etc.) and look up on their websites. They generally have an FAQ on what the beep codes mean. That might help.

The speed of the RAM is backwards compatible though. PC100 should have no problem running at 66. At least, I've never had a problem running higher rated RAM at a slower speed. Then again, it could be that the board REQUIRES 66mhz RAM, of course, I've never seen that, so it's just a guess.

I've had the problem of different brands of Ram not running together on my mobo before. The speed was the same but it would not boot with the 2 brands. Strange but it happened.