If you're developing Visual Studio 2005 ASP.NET 2.0 websites on Windows 2003 server and you're creating a separate IIS website for each project then there's a new gotcha I discovered today.

I prefer developing on Windows 2003 because at the very least you can organise your web projects more sensibly (and sanely) rather than lumping everything into the Default website. There are also many projects we undertake where we need the whole of an existing site on the dev box when we're adding new functionality - often we find absolute urls to scripts or images and unless the darned code gets to live in its own website it can be a bugger to work with.

I know there's a hack to coerce IIS on XP to have more than one Website but it's inconvenient especially when you need to switch between projects quickly (a current project is having a bunch of new functionality added to two sites which will be shared) and lets face it, it's a dirty hack.

Anyway if you start debugging a VS05 website created under IIS (you really shouldn't use the cassini based thing for anything other than knocking up quicky snippets of code, see: Cassini considered harmful (leastprivilege.com) and you encounter the error: "Unable to start debugging on the web server. Logon failure: unknown user name or bad password" then check out this kb article -

You receive error 401.1 when you browse a Web site that uses Integrated Authentication and is hosted on IIS 5.1 or IIS 6.

You also need to start the Visual Studio Remote Debugging Monitor and make sure your logon is added to the Permissions for Remote Debugging under Tools->Permissions. This seems to be a new thing because VS02/03 worked just fine without it in the past. Now please can I have the last 4 hours of my life back?

Update:

I forgot to add that the following event is logged when the vs 2005 login failure occurs -

Event Type: Failure Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 537
Date:  10/02/2006
Time:  01:40:21
User:  NT AUTHORITY\SYSTEM
Computer: UKM-W2K3-003
Description:
Logon Failure:
  Reason:  An error occurred during logon
  User Name: Kevin
  Domain:  MYSERVER
  Logon Type: 3
  Logon Process: O­
  Authentication Package: NTLM
  Workstation Name: MYSERVER  
  Status code: 0xC000006D
  Substatus code: 0x0
  Caller User Name: -
  Caller Domain: -
  Caller Logon ID: -
  Caller Process ID: -
  Transited Services: -
  Source Network Address: 192.168.100.59
  Source Port: 0