*
Load Bios with Optimised BIOS Defaults
Also reinstall old BIOS and test
Pierre
Loaded with the latest BIOS (F9) and used optimized defaults.
Still just shows 2 cores.
Problem is resolved. I went into msconfig under the general tab, and used the first radio button "Normal startup".
A few days ago I read an article to speed up the boot time. One item was to use 4 processers instead of one, another was to skip the loading of the GUI splash screen. There may have been another.
Also I've been cutting down on startup services so I put those back.
Now I have 4 processes in CPU-Z and my windows performance scores are high again.
One other point, I had ram with a special profile to run at 1600 Mhz. I left that at the BIOS default and the windows assesment scores for memory went unchanged even though running at 1333 Mhz with looser timings.
Thanks for the input F5BJR as I wouldn't have found out without reinstalling the BIOS and looking at things there.