About Thunderbolt 3 & USB-C
Thunderbolt 3 uses a USB-C connector, however, not all Windows PCs that have USB-C ports also support Thunderbolt 3. The USB-C connector is also used for other protocols such as USB 3.1 and USB 2.0, so you'll need to make sure that your computer's USB-C port supports Thunderbolt 3 before attempting to connect a UAD Thunderbolt device (via a qualified Thunderbolt 3 to Thunderbolt adapter).
Check the documentation for your PC
One way to tell if your Windows PC supports Thunderbolt 3 is to check the manual and other documentation. If the computer supports Thunderbolt 3 this will typically be a main feature listed in the manual and on the product page for the computer on the manufacturer's website.
Check your USB-C port
Some USB-C ports, such as the ones pictured below, have a Thunderbolt logo printed next to them to identify the ports as Thunderbolt 3 compatible.
USB-C ports with the Thunderbolt logo
Check the Thunderbolt 3 compatibility list
Thunderbolt 3 certified products are listed here. Make sure to select "Windows" from the Operating System menu and "Thunderbolt 3" from the version menu to filter the list for compatible results. If you're looking for a specific computer model you can further filter the results using the "Category" and "Company" menus.