Ok I read the thread and I get it now.. Perhaps the manufacturers should not place the letters "P.C." in front of server memory. Maybe it should be "SVR2100 DDR" or something along those lines for us wannabe computer builders.I picked up this H.P.TC2120 server for nothing not knowing it was different from a regular PC but it only has 128 MB RAM. I have now ordered 4 256mb ECC reg.for it. and by the way I wiped the redhat server software off of it and installed windows XP home with no problems and it seems (Other than memory issue) that is going to work as a home computer just fine. It has 2.0 ghz celeron in it and I had to install a sound card...and oh yeah it is in fact kinda big LOL. Thanks for your threads and your time to answer my dummy questions.