Thanks for taking the time to respond. I searched these forums again and found a very old post for the same problem on a different machine, and someone suggested that there was a BIOS fault, and to put the old memory back in, reboot, then put the new memory in and reboot, and under no circumstances go back into the BIOS. If it says "Memory Changed", F1 past that. Mine didn't. I now have 16GB showing in Windows and none is unavailable. Thanks again.
I've got 4x4GB Memory installed, it's recognised as 16GB by a hardware analyser(HWiNFO64), with no problems indicated. The BIOS says 8GB and Windows 10 says "16.0 GB (7.99 GB usable" My initial thought was a W10 problem, but the BIOS is saying 8GB. Bios version A03. Has anyone got any suggestions?
Studio XPS 8000, 16GB memory, only 8GB recognised by Windows 10