It's important that the PC is shut down using the proper method to keep the PC working. Failing to do so, especially pulling the plug out, can cause issues and require the PC to be replaced.
In the top left hand corner you will see VisitorRego.com. Touch this to move to Admin Mode
Note: If you have a password protected VisitorRego, then you will need to put the password into the name field (leaving the cursor in the name field) and THEN click on the VisitorRego.com icon in the bottom left.
In the top right hand corner of the desktop you will see a Shut down this PC button.
Touch this to shut down the PC.