Asrock 890GX Extreme3 + PII X2 555BE

Assembled system with stock heating and 1600 CL7 RAM.
CPU around 40C.
BIOS 1.10 + Seven Ultimate.

Enabling UCC in BIOS I get X4 but Windows can't boot. The strange thing is that I tryed any core combination in BIOS but always get lock or BSOD, even activating CORE0 only. There must be something to setup, I've left all defaults except for hdd controller to AHCI.