After installing Visual Studio 2005 RC1 on my new DEVBOX, I copied my existing projects to the new machine and had to debug an ASP.NET 2.0 application.

The detailed scenario:

I'm running a ASP.NET 2.0(.50727)  application on Windows Server 2003 SP1.
The application is running as a website in her own AppPool running under his own user account ("DEVBOX\IWAM_CodeFairway", which is member of IIS_WPG and Debugger Users).
Integrated Windows Authentication is activated for this website (and it's virtual directories).
The application worked, but when I tried to debug it using VS 2005 RC1, I got the following error message:

"Unable to start debugging on the web server. Logon failure: unknown user name or bad password."

The solution:

Click Start -> All Programs -> Microsoft Visual Studio 2005 -> Visual Studio Tools -> Visual Studio 2005 Remote Debugger:

Then click "Tools" -> "Permissions" and add "DEVBOX\IWAM_CodeFairway". Grant "Debug" permission and click ok.

Visual Studio Remote Debugging Monitor can also be installed to run as a windows service. More details on this are in the help file.