Vista - 1 CPU detected in dual core system. -Solution

Background:
After reinstall of VISTA Ultimate the experience index has dropped from 5.3
to 4.4 with the CPU giving a lower score than previously. The task manager
only shows one pane for CPU performance in place of the 2 shown previously.
The processor is reported correctly as Intel core 2 CPU 6600 at 2.40 GHz in
Control Panel\System and Maintenance\System. The mother board is a Asus P5K.

Solution in this case:

There seems to be a number of causes that prevent VISTA seeing both cores. I
don't understand the reason that the following works so an explanation from
someone would be helpfull.

Start>Start Search>msconfig
Boot Tab
Advanced Button
The startup number of processors was set to 1 and could not be changed
Unchecked the number of processors checkbox
Check Detect HAL box
Click Apply and Reboot
After reboot the number of detected cores were 2

(Checked with Intel Utility that it detected 2 also task manager now showed
2 and windows experiance index increased from 4.4 to 5.3)

Unchecked detect HAL and selected 2 as number of processors.

Checked make all boot settings permanent under Boot tab.

Reboot

Now BIOS also reports 2 cores instead of previous 1.

I just noticed that my dual-cpu dual-core (Xeon 5130 with 4-cores) shows
lower cpu index just recently, and task manager only shows 2 panes (I'm sure
at one time it showed 4).

"jaerha" <jaerha@xxxxxx> wrote in message
news:9CDDDBAD-18E5-4A3E-BB73-BE7EB1A02185@xxxxxx