enable AMD-v on Asus M4A88T-M with AMD Phenom II X6 1090T
According to this ASUS calls the setting "Secure Virtual Machine Mode" in the BIOS. According to your manual, it should be listed under Advanced / CPU Configuration. There is a German manual on the ASUS site if your BIOS uses that. The German manual calls it "Secure Virtual Machine Modus" or "SVM".