id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 5639,AMD-V not working,palomino,,"Cpu: AMD AthlonIIx3 425. Motherboard: GA-MA78GM-US2H HostOS: Ubuntu 9.10 GuestOS: Windows 2003 (2 processors allocated) Virtualization is enabled in BIOS. When i upgraded to 3.1.0, it reported ""VT-x is not available. (VERR_VMX_NO_VMX)."" when i tried to start the guest os. 3.0.12 worked fine. Reinstall 3.1.0 can not fix the issue. Remove 3.1.0 -> install 3.0.12 -> remove 3.0.12 -> install 3.1.0 works. But if I restart the computer, I have to do that again. BTW: It did not happen on another computer with intel's cpu. ",defect,new,VMM/HWACCM,VirtualBox 3.1.0,,AMD-V,,Windows,Linux