Couple of points.
The lack of menu's etc does not mean that it is compiled. They are very easy to turn off actually. Given that you are using a VNC connection to a windows box I do not know if this will work or not but holding down the shift key while starting an access application will bypass the start up options. (though that is simple to disable as well.)

If the app is an exe file then it is compiled otherwise it is not. Given that you stated the app has multiple users then I am going to assume it is running on a client/server model. wherever the back end resides may well have a copy of the front end as well.

Personal sode note: Access can be a very robust platform for a small busines. Though it is not a great web back end. A well programmed Access (both front and back end) app can have 50 concurrent users and run pretty smooth. But, I am biased since I am a professional access developer. Access is alos a wonderful RAD tool. IMHO

Almost forgot to add www.dbforums.com has a wonderfull and helpfull base of users.