My mom's "old faithful" has been always suffering from its low RAM of 64Mb. I thought an addition of 16Mb would help it a little bit. I installed the used DIMM I bought from an internet auction. At startup the computer said this: "At least one memory DIMM does not support serial presence detection". What is this? How do I know what kind of memory this computer needs? I don't want to remove the only working DIMM unit because it's in a difficult place and I'd probably break that DIMM or damage the circuitry. The computer is HP Vectra PC 6 with Pentium Pro processor and Windows 95 C. The 16Mb DIMM I bought had this text in front: EK16SDRAM746M 16M/32M DIMM MODULE 48.37302.011 Made in Taiwan R.O.C. In a sticker at the back is this: DIMM (16MB) 02K2288 11S5511019E21AE112PC. I hope you can help, I am getting frustrated with this... surfing with the broadband with firewall and virus softwares running is sometimes slow and bootup takes ages...

Download CPU-Z and it should tell you the type of ram you have. You could also take out the ram that was in your computer and see what type that is. If it's an older computer, its either PC100 pr PC133.

"If it's an older computer, its either PC100 pr PC133" No, this machine is older than that. DIMMs weren't even classified as PC66, PC100, or PC133 back then, they were just called DIMMs, either FPM or EDO...the early ones ran at 5v. Were there already 2 sticks of RAM installed? It's possible that the old Pentium Pro required RAM installed in pairs & it may even have to be ECC. Serial Presence Detection (SPD) is info stored on a chip on the RAM module...the BIOS reads the info & then autoconfigures the DRAM settings based on this info. This will explain in more detail: http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci533524,00.html This space for rent

Go to www.crucial.com and you can look up exactly what type of memory you need and how much your MOBO can handle. Soylent Green is PEOPLE!!!

Thanks for that Crucial.com link! That helped a lot. At the same time I could check the suitable memory for my computer too (with ASUS A7A266 processor). I was surprised this one had 3 168-pin DIMM sockets and 2 184-pin DIMM sockets. According to BIOS Agent's info about my memory (slots: 1-0, 2-0, 3-0, 4-256Mb, 5-0) I guess this machine has one of those 184-pin DIMMs installed. Before this I didn't know those existed! I gotta head for the computer store and get loads of new memory for these machines! I can't even imagine what the HP Vectra would feel like if it had enough memory... it's been always so slow! Better late than never. :) BWT, [/b]jam[/b], DIMMs did not run on 5 volts, SIMMs did. I read it from a PC book. In the Vectra there's three DIMM slots and only one DIMM installed. That's what Pentium Pro can handle. (I read that from that book too).

Glad I could help. Thanks for posting back. :) Soylent Green is PEOPLE!!!

Get another book. Early 168-pin FPM & EDO RAM ran at 5v. The 3.3v SDRAM standard was adopted later. And *some* socket 8 Pentium Pro motherboards required that 168-pin DIMMs be installed in pairs. 72-pin SIMMs almost always have to be installed in pairs. This space for rent