I have to write an application that must have the ability to update itself. The application itself will be running 24/7 and I had thought of writing a service but because of the need to auto-update, I think a windows application would be better. The application sits on a remote machine running windows, but the auto-update must have no user interaction whatsoever.
The application will be running in a vending machine and it's job is to send data back to an ftp server over GPRS, but as new functionality is developed, the application needs to update itself, and either download the new version from ftp or http.
So, my question. What's the best technology to implement the auto-update with? The application will be written in C#, but I'm not sure whether to use ClickOnce or the Application Updater Block. The clients must have at least .NET 2.0 (as I need to use the serial port for AT commands to the GPRS modem).
ClickOnce might look like the one to go for, but I don't know how to get around the user interaction part. Also as the application is running 24/7 I'd prefer to update itself as it's running, or perhaps set a time (eg. 3am when the shops are closed) to have the application stop and restart itself (how to do that is another issue...!)