I have prepared a couple of USB sticks for Windows 10 installation. Since I am quite lame on labeling stuff, I lost track of which stick is for new UEFI-enabled machine and which one is for legacy BIOS boot. I can definitely do it all over again only if I can still find the image file I downloaded before.
The key to finding out if the installation USB drive is UEFI bootable is to check whether the disk’s partition style is GPT, as it’s required for booting Windows system in UEFI mode. And there are a few ways in Windows that you can use to quickly find out.
Option 1: Disk Management
Open Disk Management tool, right-click the Removable Disk that you are checking and choose Properties.
Switch to Volumes tab and check the Partition style field there.
Option 2: Command Line
You can also use the powerful DiskPart command line to find out as well. Open Windows Prompt window, type DiskPart and enter. Then type:
The asterisk in the GTP column indicates that the disk is GPT partitioned.
Option 3: PowerShell
This is probably the easiest way to find out the same information. Open PowerShell console, and simply type:
and check the Partition Style column.