PC's been fine since it was built about 3 years ago. 3 x 256mb Crucial PSC2100 DIMMS equalling 768mb.

Now it only registers as 640mb. No errors just changed. Coincedence its exactly 128mb off 768mb???

Simon.

 

Does your motherboard have onboard graphics or do you use a separate graphics card?

If the former, then it's possible that you have managed to allocate an amount of RAM solely to graphics. Have you changed anything recently?

K.

 

if not you could try taking 1 dimm out at a time and see if they all make a equal difference, one of the chips could have died ?