>>>I'm calling Application.Restart(). On my development PC this works (of course) but on my test box the app shuts down but doesn't restart.


>>>Are you sure that it shuts down (cleanly and completely)?
>From what I can see yes. I look in TaskMan and it's gone.

Can you check whether the new instance makes *any* attempt to start (e.g. does Main() run) ? No exception handling that might conceal startup problems? Bear in mind that the new instance starts up before the old one is fully disposed - could the old instance be preventing the new from accessing some resource?


>>>Can I ask why you are using Restart() ?
>I'm detaching & reattaching the app from the DB.

Using Restart() sounds like a pretty drastic way of achieving that? I've only used Restart() in situations where the binaries have changed (e.g. ClickOnce deployment)