What we absolutely must know

1. What is my CPU. Identify it and make sure it's at least a quad core. TAKE A LOOK AT CPU-World
2. Check if the 'virtualization parameters' are enabled on BIOS
3. How much memory I have. Check the RAM and verify that is at least 4GB.
4. The amount of free space on my HDD.Launch gparted and make sure you have a partition with at least 20GB free. While you're there add a label to the partitions to better recognize them even by name.
5. The minimum hardware requirements of the operating system you want to install as a virtual machine.