Is it possible to debug Global.asax?

1. Attach the debugger to the IIS process.
2. Open the global.asax file and put in a breakpoint.
3. Add a space to the web.config file and save the file (this causes the current web application to reset);
4. Refresh / goto a web page on the site.
5. watch in amazement when the debugger stops at your breakpoint. :)

A simple way to break in Application_Start() is to use the System.Diagnostics.Debugger class. You can force the application to break by inserting System.Diagnostics.Debugger.Break() where you would like the debugger to break.

void Application_Start(object sender, EventArgs e) 
{
     System.Diagnostics.Debugger.Break();

     // ...
}