i have a gateway essentials 933 that i have had for about 2 years. i used to run my pc with two memory sticks of 256mb of sdram ram with dimm slots. these were the pc133. when i went to upgrade my memory i bought 2 sticks of 256mb of pc133 ram(pny). after i installed it, my system wouldn't boot. i brought the memory back and got 2 256mb of pc100. the system booted fine and i have not had a problem since then. my question is if the old memory was pc133 why didn't the new pc133 work with my system? is there much of a difference between the two? i can't notice it.

proprietary hardware...i ran into the same problem in adding memory to an older compaq presario...they do it that way so you have to buy memory from them...makes it difficult to upgrade

jajarnutter, I think the only real difference between the two is bus speed. Sounds like your machine prefers the 100 mh. Maybe you are stuck with 100? Maybe you can adjust it in the BIOS? Justin? Dave? Ed in Texas.

thanks for the replies. looks like im stuck with the pc100. there is no way to change the settings in by bios unfortunately.

Just a question, and observation. You have four places for memory? (you tried adding 512MB to 512MB. total of 1024MB) New PC133, is not backwards compatible. (not all, are like this) So, if your computer is meant to use PC100, and you had PC133 that would do 100. That's probably what it was doing. You got new PC133, that wasn't backwards compatable. Trouble. Also, you get into density, ect. A lot of different things ;-) Is there a setting in your bios or, on your motherboard (jumpers), to change. Like Hostclk+PCIclk......... nevermind I guess you investigated that.

thanks I'll Try . i only have only two dimm slots. the max i can put in is only 512 according to the owners manual.if there is a way to increase it i would. the brand of memory is PNY and the old brand is some kind of generic brand that came from Gateway.

jakarnutter, "i used to run my pc with two memory sticks of 256mb of sdram ram with dimm slots. these were the pc133. when i went to upgrade my memory i bought 2 sticks of 256mb of pc133 ram(pny)." Ok, I guess, I misunderstood about how much RAM you had, and what was being added. Because, if you were upgrading(adding), and you had two sticks of 256MB, and bought two more of the same size. That's what made me think you had four slots. I didn't check but, most likely on the PNY site, it might have some mention, of what I had said about the new PC133. But, that's all water under the bridge. Good Luck