Problem installing RAM. First of all the machine is maybe four years old. IT was running on 32MB RAm but the other day I put in another 64 and so it showed the total was 90MB RAM. This morning I took out the 32MB RAM and inserted the 256MB RAM so the total should have been 320MB RAM if my math is correct although when I checked the machine was only showing 160MB - half. So I took out the 64 thinking there may have been something wrong and now with only the 256 chip in the machine shows 128MB RAM. I have read a few different posts conerning this but have been unable to find a solution, any suggestions? I have also went through msconfig and changing the "limit memory to ?MB RAM" box with no luck,

You should probably ask this in the hardware forum but it seems likely that your mobo does not support the type of RAM you have installed. Have a good look at the stick. Does it have only eight chips on one side or is it double sided with eight on each side? The former is High Density and the latter is Low density. It's likely your 4 year old mobo only supports low density. Mine's like that and double-sided low density RAM is becoming hard to get and about one and a half times more expensive than high density.

Also you can get PC66 PC100 and PC133, theoritically it should be interchangeable, but would advise check the Crucial or kingston websites to see what they recommend. Does you MoBo support 256MB sticks?

Many older motherboards only support "registered" memory. As with mine, if you put "unbuffered" non-ECC memory in it will show up as half the size. It's not always true, but single sided sticks are ussusaly "unbuffered" especially in the 256M and higher range.

I have had the same problem. The reason was that the chipset didn't support more than 128 MB. You can look it up in the manual of your motherboard. It probably says that the maximum of memory is 284 MB and that is exactly 3 * 128. There is nothing wrong with your RAM's, but I advice you to use RAM's with the same speed, (100 or 133 MHz), using RAM with different memorysize doesn't matter at all.