Make Tech Easier published a tutorial about converting legacy BIOS to UEFI in Windows 10.
How to Convert Legacy BIOS to UEFI in Windows 10
In previous versions of Windows, you were forced to reinstall the entire operating system if you wanted to convert Legacy BIOS or Master Boot Record (MBR) to UEFI or GUID Partition Table (GPT). However, in Windows 10 Microsoft, a new and simple tool called MBR2GPT was introduced. It lets you convert from Legacy BIOS to UEFI with just two commands.
How to Convert Legacy BIOS to UEFI in Windows 10
