The usual way is to uninstall that application (and similar) completely, then...
Don't forget to log out from everywhere.
...then the administrator of the device creates a system account for you, you choose your password, etc., you log into your new system account, install the stuff under your user folder ("My documents" or something; NOT for all users), blah-blah-blah, and use that new system account of yours from now on.
Have you noticed when you blop on a "turn computer off" whatever button, you're offered three options.
Well, right, it's in the Start menu. "Log out from the system" is one of them. It's it: after you've got your account, you use it, then you log out; need again - log in, use, log out.
The thing was invented exactly for shared devices as in your case.