virtualbox.org

HOST: i7 620M. All BOIS feature opend. Win8 RTM.

Hardware accelaration is disabled, in every VM's setting page, the tab is gray.
CPU can not be more than one core.

Everything is well when my host is win7. After migrate to win8. Hareware accelaration is disabled.

Any one has the same problem? Or any suggestion？

Have you enabled the Hyper-V feature?

Yes.

But when i found hardware accelaration can not be used. I removed Hyper-v role, and reinstall virtualbox. but the tab is still disabled.