When your computer is having a UEFI , it will prefer a GPT (GUID Partition Table) on the harddisk to function. GPT has advantages over MBR (Master Boot Record) such as support for larger disks.
Start the diskpart.exe and run the command:
When there is a star in the Gpt column the disk is Gpt, else it is an MBR disk.
(Example of a disk without GPT)
More information about the difference between GPT and MBR can be found on the Wiki pages: