GTS Online servers disable the right-click ability. These directions show how to change your default Windows printer without the need for the right-click feature.
Setting your default printer
Open the Devices and Printers shortcut located on your desktop.
Click once on the desired printer to select it.
At the top of the screen, click on See what's printing
On the new window, click on Printer > Set As Default Printer
Your desired printer has not been set as the default Windows printer