okay, so i attempted to unlock the other 2 cores on my AMD Phenom II X2 550 BE with a Biostar TA790GX 128M [BIOS = 78DEA113]. now while i was doing it, i was in the O/S Windows 7 Ultimate 32 Bit. so i used the program to update the BIOS normally which was the one found on Biostar's website. it changed the BIOS, and then i turned ACC on. when i tried to boot into Windows 7, it wouldn't . it just showed me a black screen . i've tried clearing the CMOS, and changing the settings back to default. i don't have a floppy drive so i can't really do much. the nice thing was, my sub HDD that had Ubuntu but i changed to Windows XP somehow boots? so then i tried the process again and i successfully got 4 cores. now i just want to know, what can i do to try to boot back to Windows 7? i haven't tried switching the sata cables then booting to Windows 7 again yet... but i am gonna stick with Windows XP until i get an answer.