I was working in IIS, today, and came across an issue where it was attempting to load my site in ASP.NET 1.1.xxx. I, for one, know that the site I was deploying was built as a precompiled web from VS2005, which, as far as I know, means that it's .NET 2.0 for sure. I also knew that all of the assemblies I was referencing were .NET 2.0 and the web config had all the appropriate .NET 2.0 love.
The first thing I did was search around IIS to see if there was a way to beat it into submission and force it to run the site in ASP.NET 2.0. No luck... I believe the newer versions of IIS have this functionality, because I swear I've used it before, but I wanted to deploy now!
After a bit of searching, I came across this great little utility called ASP.NET Version Switcher that saved me a boatload of time by Denis Bauer. It shows all of the sites in IIS and easily lets you switch the .NET Framework version for any one. Granted, it just runs the command line utility that I'm sure is easy enough to figure out, but GUIs are nice too.