Do you have a debugger installed on the computer running the crushing app? if so a message box should appear, through this msgbox you should be able to attach the debugger...
ELSE ( concerning you have a debugger installed )
You could also:
1. Start your application through Debug->Start, this will require you to specify the executable to be debugged at the project settings.
2. You could also put a message box on the app startup, this way you could attach the debugger after the application was started ( through Debug->Process->... ).
The latter option should be used to debug a mixed mode DLL, where managed and unmanaged are used together…
ELSE ( concerning no debugger is used )
You could use AutoStack Tracer to get the stack trace of the upon crush, you can get the tool freely from http://www.ddevel.com/Home/main.asp?Proj=StackTracer/AutoTracer.asp

Hope this help

Nadav