Originally posted by: sswilson
There's a process to get windows to have a second look at how many cores there are (google), but if it were me I'd just do a fresh install.
I had this problem too on a Gigabyte 890 GX mobo. I'd been troubleshooting and turned on "Bootlogging". I spec'd "2 cores" and "maxmem". This was fine. However, it added to the boot.ini file /.../bootlog /maxmem=2048 /numproc=2
When I decided to try running 4 cores again, it kept seeing /numproc=2 and even though bios had all the settings OK, as soon as windows started - poof! two cores lost.
So I changed the boot.ini file back - removed bootlogging, BUT left /numproc=4 and presto - 4 cores are running again!!! [Phenom II BE550]
I think a lot of people are having this problem if still running XP. Cheers
Maxing Clocks Is Sweeter Than Sex!!!