Browser Based Offline App With Database Connectivity

I work for masterclock. We sell network synced clocks and timing systems. One of our products is a "bell ringer." We currently control this ringer through a C++ program another one of our employees made. However, it only works on Windows systems, looks like crap, and is as confusing beyond all get-out. I have been given the task of rewriting this program in a pretty, easy, and universal format. i.e. a browser. Now to further explain the bell system program.

1. The program searches the local network for the bell system hardware.
2. User chooses appropriate hardware (if more than one bell system exists) to connect to and enters the password.
3. User edits tables stored in a local MS Access database via the bell system program UI.
4. User sends data to the bell system hardware it is connected to.

I've been racking my brain and the internet for about 6 hours trying to see what is possible. Because this all needs to be done locally I can't use any sort of server-side language like php or asp. It seems silly to make a client install a virtual server to connect to a file that is on their own computer. I'm assuming that I am pretty much limited me to javascript. I found this site but that only works with internet explorer which is almost as restricting as the program we have now.

I considered flash for a little while until I found out a swf can't connect to a database w/o using php or asp. We aren't limited to the MS Access database but it would be less work for me if we could stick with it. It may not even be possible but it seems like it should work. some way. We also considered an internal site on the bell ringer hardware itself, like routers nowadays. I think that would be an equally if not more difficult process though and I'm limited to about 500kb on its flash memory.