Vista - CPU core 2 not working on Vista 64bit

I have an Asus G50VT with an Intel P8700 Mobile 2.53Ghz and 4G Ram....

For the past couple of days I have noticed that my computer has not been performing right! Only one core is working, Core 1!!!

I have checked all Processor power management and performance utilities and nothing happened! I have checked the bios update and Device management, the Processor stil shows 2 cores!!

Can someone help me with this? I dont think anything is wrong with the processor, it must be Vista!!

thanks in advance

"ironballs" <guest@xxxxxx-email.com> wrote in message
news:9dc44580c96dab2362749a248b09b041@xxxxxx-gateway.com...Unless the software load requires it, only one core, Core 0
usually shows any activity. Also, apps have to be coded to
use more than one core. If you really want to test your cores,
go to http://www.sisoftware.co.uk/ and download Sandra 2009
Lite, the free version. Run the multicore efficiency benchmark
with the Task Manager performance window on top, and you
will see both cores running at 100%.