To roll-back a PC from the desktop shortcut:

1. Right click the Rollback Rx icon in the system tray, select "Rollback system" from the popup menu. Select a snapshot to rollback the system to. You can also choose to take a snapshot of the current PC by checking the "Take a snapshot of the current PC before rollback in case I want to come back" checkbox. Click on "Next" to continue.
 
2. The computer needs to restart to rollback to the snapshot. Click on "Restart" to continue with the rollback.