CPU Core issues

Can someone help me out here i am having a little trouble with my CPU.

Recently i upgraded my computer's mobo n graphics card. However when i installed Vista i noticed that only 1 core was functioning. on the old board the both cores always were working. The CPU is a e6700 2.67 Ghz and the mobo is an nForce 750i FTW.
also in the task manager i dont have the 2 boxes for the individual cores its just the one.
i made sure its enabled in the bios and that the bios is up to date, it not quite up to date but its pretty new.
i understand some programs only use 1 core but this definately isnt using both.

any help would be much appreciated

What's you cpu-ID in cpu-z? Go into device manager and tell me what it says under processors and how many processors you see there. Sometimes when rolling out an OS, it doesn't recognise all the cores.

thankyou all very much for your help. however i have fixed the problem. Whilst reinstalling vista (the cure). i found a possible fix is contained in the Msconfig/boot/adv options there are a few things you can do here. select the number of cores you have or you tick the check box detect hal. anyway thats if anyone else asks you the same question.

dont forget we are talking about vista here....it can be real pain. I am still trying to stabalize my system.

yeh iam on 32bit. i heard there were a lot of issues with the 64bit. compatability problems everywhere but that was about 6 months ago. i am curious as to what the difference is.

ah well thats good to know actually. Do you know of perhaps how much faster or differences it has over the 32bit version? advantages?

sux you have to buy another version of vista if you want 64bit, i mean i purchased home premium 32bit upgrade which is pretty much a full disc anyway.

it must use the full potential of the cpu too becuase i have a 64bit capable system but limted to 32bit...anyway this stuff should probably be on another thread.