Step 1:

Open windows taskbar, click the Settings Icon then search for proxy selecting Change Manual proxy server settings

 
Step 2:

Click Proxy from the Left menu.

 
Step 3:

Now toggle "Use a proxy server" from the middle of screen as shown menu, and setup proxy using HTTP/HTTPS Address found here and the correct port. TorGuard recommends HTTPS as it is more secure.

 

Step 3b:

In below Example we used  HTTPS Address https://fr.stealthtunnel.net with port 443, note that we added https:// before the address to tell windows to use HTTPS.

Step 4:

Click OK and then OK again - now browse to any website, it will prompt to enter your TorGuard Premium Proxy service sername and password - if your not sure of those, they can be managed here

Step 5:

Browse to TorGuard Whats My IP and confirm your IP has now changed.