Using IIS6 on a Windows 2003 Server. I launch Visual Studio 2008 to debug on a custom webserver and I got the error "Unable to Start Debugging on the Web Server". I screwed around with a bunch of suggestions to no avail. I then tried the follow:
Specify host names (Preferred method if NTLM authentication is desired)
To specify the host names that are mapped to the loopback address and can connect to Web sites on your computer, follow these steps:
Set the DisableStrictNameChecking registry entry to 1.
Click Start, click Run, type regedit, and then click OK.
In Registry Editor, locate and then click the following registry key:
Right-click MSV1_0, point to New, and then click Multi-String Value.
Type BackConnectionHostNames, and then press ENTER.
Right-click BackConnectionHostNames, and then click Modify.
In the Value data box, type the host name or the host names for the sites that are on the local computer, and then click OK.
Quit Registry Editor, and then restart the IISAdmin service.
This fixed it, answer found here: