First, it's not a good idea to try and use 72 pin SIMM and 168 pin DIMM or SDRAM at the same time, if that's what you're trying to do.
Second, some motherboards will not use double sided memory, only single sided.
Third, sometimes you have to go into BIOS, exit and save changes, without changing anything, just to let the BIOS know the new RAM is there.
A motherboard manual might help too...
If you had everything...Where would you put it?
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