Modern CPUs include hardware virtualization features that help accelerate VirtualBox, VMware, Hyper-V, and other virtual machine applications. But Intel VT-x isn’t always enabled by default.
If it isn’t, you’ll see a message like “VT-x/AMD-V hardware acceleration is not available on your system,” “This host supports Intel VT-x, but Intel VT-x is disabled,” or “The processor on this computer is not compatible with Hyper-V.”
Intel VT-x May Come Disabled; AMD-V is Always Enabled
First, this is only necessary for Intel VT-x. The Intel VT-x hardware can be disabled via a BIOS or UEFI firmware setting, and it regularly comes disabled on new computers.
AMD-V is always enabled if you’re using an AMD processor that supports it, so there’s no BIOS or UEFI firmware setting you need to change. However, if you have another hypervisor (like Microsoft’s Hyper-V) using AMD-V, you may see a message saying it’s not available.
Try Uninstalling Hyper-V
This error message can also occur if you have Microsoft’s Hyper-V installed. When you haver Hyper-V installed, Microsoft’s hypervisor takes over and won’t let VirtualBox or VMware access the Intel VT-x hardware. You’ll see error messages about Intel VT-x being unavabilable, even though it’s enabled on your computer.
To solve this problem, head to the Windows Features window in the Control Panel and uninstall Hyper-V. Reboot your computer and try using VirtualBox or VMware again.
Yes, Hyper-V reserves the hardware features as long as it’s installed. You’ll have to uninstall it if you want to use VirtualBox or VMware along with your CPU’s hardware virtualization features. It doesn’t matter if Hyper-V is closed — it’s reserving the hardware in the background.
Access the BIOS or UEFI Firmware
You’ll now need to access your computer’s low-level setup screen. On PCs made prior to Windows 8, this is probably a BIOS. On PCs made after Windows 8 came out, this is probably UEFI firmware.
On a BIOS-based system, you’ll need to reboot your comptuer and press the appropriate key while it’s booting to access the BIOS setup screen. For example, this is often the “Delete” or “F2” key. It may also be “Esc”, “F1”, or another key.
You may see a message like “Press [Key} to access setup” on your computer’s screen while it boots. Perform a web search for your computer’s model number and “access BIOS” or examine your computer’s manual if you can’t find the key that works.
On a UEFI-based computer, you can’t necessarily just press a key while the computer is booting. Instead, you’ll need to follow these instructions to access the UEFI firmware settings from Windows 8’s advanced startup options. Hold down the Shift key as you click the Restart option in Windows to reboot straight to that menu.
Either way, once you’re in, you can begin looking around for an Intel VT-x option.
Typically, you’ll find this option under the Processor submenu. That menu may be located somewhere under “Chipset,” “Northbridge,” “Advanced Chipset Control,” or “Advanced CPU Configuration.”
Look for an option named “Intel Virtualization Technology,” “Intel VT-x,” “Virtualization Extensions,” “Vanderpool,” or something similar. Enable the option and select “Save and Exit” or the equivalent feature to save your settings changes and reboot your computer.
What to Do If You Don’t See the Option
Unfortunately, some laptop manufacturers and motherboard manufacturers may not offer an option that lets you enable Intel VT-x. The setting may be disabled by default with an option that lets you enable it.
If you don’t see the option in your BIOS, try performing a web search for the model number of your laptop (or your motherboard, if it’s a desktop PC) and “enable Intel VT-x”.
In some cases, manufacturers may later release a BIOS or UEFI firmware update that enables this option or provides you with an option to do so. Updating your BIOS or UEFI firmware might help — if you’re lucky.
And, remember — if you have an older processor, it may not support the Intel VT-x or AMD-V hardware virtualization features at all.
Image Credit: Nick Gray on Flickr