Hi,

I recently upgraded my CPU from Athlon 64 X2 to Phenom II X4. Everything runs fine, except that Windows Vista only recognized 2 cpus instead of 4 cpus. I run dual boot with Windows XP, and there's no problem in XP. All 4 cores detected, with CPU-Z v1.50. Any suggestion?

My rig :
Phenom II X4 940 @ 18x200
Gigabyte MA770-UD3
Corsair Dominator 2 x 2GB kit PC8500
MSI GeForce 9800 GTX+ 512 MB

I forget, i use Vista Ultimate SP1 and XP Professional SP3

Problem Solved, changing in msconfig at boot tab and advanced boot option.