HI, i had the same problem on an Asus P6T6 WS REVOLUTION MB, what I did was go into MSCONFIG, boot, advanced options and checked the box for cpu and put it on 4, that's all that showed, unchecked the box, hit apply and restarted, now my cpu-z, everest ultimate and taskmanger show all 4 cores and 8 theads, hope this helps, good luck, and if it should be showing something different then what I've posted ,could someone please let me know, and how to go about changing it, tyvm people, laptopluney08
I followed the advice of the guy that responded to you post, by going into MSCONFIG, boot and advanced options however my option said 1 processor not 1 core and 1 processor is correct but I deleted it left it blank and rebooted. When windows opened up I checked cpuz and core temp and both report 4 cores a nd 8 threads the way it should be. So i tip my hat and say thank you to Laptopluey8. I suggest you try his method because it worked for me.
I had the same problem arise 2+ years after you: should have seen 8 "cores" but saw only 2.
Tried your MSCONFIG work-around and it worked for me. I don't understand why that worked, but thanks for posting.