on boot up, I get a flashing message in bright white letters saying Warning : SPD not found at DIMM (s)1 What does this mean and how do I correct it? I am running a 400 mhz processor with 160 megs of ram and windows 98 se captng1

I'm not sure what the letters stand for but SPD is the identification of your memory modules. Your BIOS can't tell what kind or size that memory module is. Either the module is defective or the contacts may have oxidation on them. Try removing and polihing the memory module contacts. Then install and remove 4 or 5 times to scuff up the contacts in the MBoard DIMM socket. If that doesn't work check the settings for memory in the BIOS to see that they are correct. Otherwise you may have a bad stick of RAM. Does the computer boot anyway or stop at that point? If it doesn't boot you could try to remove ALL RAM and then try one stick at a time. If you have the manual for the MBoard look to see which memory socket is #1 and concentrate on fixing that one or not using it at all.

If this just started happening without you having made any changes then it may be a bad SPD chip or connection, as OtheHill says. If you just added a new stick of RAM it may be an older one that doesn't have the SPD info. In that case the bios may show the correct size but be unable to determine if it's PC100 compatible, which is what your PC needs.

Some old DIMMs (e.g. some FPM or EDO) don't have the tiny chip the SPD info is stored on, or the module was generic and no info was entered on the chip. If you look at the top edge of the modules the tiny chip is about 1/4"(6 mm)square and on one side near the top of the module on the very end after the last ram chip. If one module has no chip like that, that's the one the bios is complaining about, but they may all have that chip but one is blank of info. In most bioses you can either have the ram set up automatically according to the info on the SPD chip, or you can set the ram speed and CL2 or CL3 setting manually. The bios will run all the ram at the speed and CL of the slowest module, if one is slower. Try setting the ram speed manually, going by the labelling on the module. If it doesn't say whether it is CL2 or CL3, try CL3 first. Remove the power to your case whenever you are going to change any connections or remove or install any ram or cards. If you do have a module with no SPD chip on it, it is probably a FPM or EDO DIMM module. EDO is up to about 10% faster than FPM, but all the ram must be EDO in order for the ram to run at that speed. SDRam DIMMs are accessed at up to 4X as fast as FPM ram. If you can replace the module with no SPD chip with a SDRam module, your ram will be accessed much faster.