Besides,
The IIS5 that does ship with XP is not a pure IIS5 environment. Most of your underlying DLL files have changed.
Get Win2K pro, SP2, and the other 17MB of patches, and patch the living hell out of that box.
It will run better than XP would. I've played with MS too much to ever want to install MS software previous to Service Pack 1.
Meanwhile, my mother didn't listen and got XP Home on her new dell. Ouch.
I used XP, I qualified a bunch of apps that performed well under it, and it fixed the MFC42.DLL problem that has been the bane of my existence with every Windows version.
It even fixed a bunch of suspend-mode and APM problems, and older apps perform well under it.
Would I use it for a server? Hell no. Do I use it now? See previous answer. It's a nice OS for people that need to run Access 97 and Foxpro apps next to Office XP Pro and Visio 2002, but it's not for me.
Besides, I'm just starting to get really good with 2000 Pro and Server, as crazy as they are
.
However, you won't see me switching BIND over to XP from OpenBSD any time soon