Before attempting to use acceleration, you should first determine if your CPU supports one of the following virtualization extensions technologies:
Most modern computers do. If you use an older computer and you're not sure, consult the specifications from the manufacturer of your CPU to determine if it supports virtualization extensions. If your CPU doesn't support one of these virtualization technologies, then you can't use VM acceleration.
Virtualization extensions are typically enabled through your computer BIOS and are frequently turned off by default. Check the documentation for your motherboard to find out how to enable virtualization extensions.