failed to open a session for the virtual machine

i have this problem when opening a virtual machine in virtual box:

    Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED).


Result Code: 
E_FAIL (0x80004005)
Component: 
ConsoleWrap
Interface: 
IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

i searched for a solution and i found that i must enable the virtualization from the the BIOS setup but when i checked it i found it enabled. can anyone provide me a solution?

Start your PC, press F2 or F12 or DEL, go to the security option and enable VT technology. In some new BIOS, it called Virtual technology or Intel virtualization in the CPU setting option