I recently had to install IIS on an XP Pro machine with service pack 2 and .NET already installed.
 
All in all it was quite an annoying and time consuming ordeal for something that was supposed be a walk in the park.
 
Here is the list of the problems I encountered and the solutions I used:
 
1. Unless you are extremely lucky you will probably run into the infamous IIS installation bug.
 
I got the following error message while trying to install IIS:
 
“Setup cannot copy the file staxmem.dll...”
 
To solve this problem follow the instructions in the link below *:

http://support.microsoft.com/default.aspx?scid=kb;en-us;894351

 * Note that they offer 2 solutions and for me solution number 1 didn’t work so I had to go for solution number 2(merge XP setup and SP2 setup). I hope you will be luckier and avoid the need to download SP2 and merge it with the original XP installation files.
 
2. After installing IIS. Dot Net needs to be reregistered in order to work properly.
 
I got the following error after installing IIS and trying to run an ASP.NET web project:
 
“System.Web.Hosting.HostingEnvironmentException: Failed to access IIS metabase. The process account used to run ASP.NET must have read access to the IIS metabase (e.g. IIS://servername/W3SVC). For information on modifying metabase permissions, please see http://support.microsoft.com/?kbid=267904.”
 
I had to run the following command line to reregister .net 2.0 and make it work properly:
 
C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe –i
 
You can find more info about aspnet_regiis.exe here:
http://msdn2.microsoft.com/en-us/library/k6h9cz8h(VS.80).aspx

 3. After all that, debugging still did not work because my IIS default authentication options did not include integrated windows authentication.
 
I got the following error:
 
“Unable to start debugging on the web server. Debugging Failed Because Integrated Windows Authentication Is Not Enabled…”
 
To fix this go here:
http://msdn2.microsoft.com/en-us/library/x8a5axew(VS.80).aspx

I hope this will save some one else, some time, some day…