I'm trying to get the default IIS welcome page to come up, after I messed up the configuration trying to get ASP.NET to work. (I eventually figured out that it wasn't installed, and installed it, but I don't know exactly what I did that messed things up, and I don't know how the installer handled the weirdness I introduced.) When I browse to the page, I get a bare-metal "503 Service Unavailable" message, and in the event log I find "Failed to find the RegisterModule entrypoint in the module DLL C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll. The data is the error." (where "the data" is something along the general lines of 0x7F000000.)
I've tried registering ("aspnet_regiis -iru"); I've messed around with the modules and handlers until I can't see straight (doubtless that was the original cause of my problems -- I tried to install the modules and handlers and what not that ASP.NET would require before realizing that ASP.NET was just not installed), and I don't really have any more ideas.
Also, I looked online somewhat, but I found no sign that anyone else in the history of mankind had had anything like this problem with ASP.NET.
Final notes: I'm running a .NET SxS installation with Frameworks 1.1, 2.0, 3.0, 3.5, and 4.0b1 installed (yes, perhaps a bit much... I'm looking slant-eyed at 4.0b1 as we speak), along with Visual Studio 2005 Standard, Visual Basic and C# 2008 Express, and Visual Studio Professional 2010 Beta 1. Cassini (aka ASP.NET Development Server) was working well enough before-hand (and hopefully still is), but there was enough of a difference between debugging on it and running the app in IIS 6 that I decided I needed to be using IIS at least for best results.
It will probably be necessary to post the config file, but I'm not entirely sure how to trim it down to just the interesting/broken parts. Any suggestions before I wade in? (I'm not experienced in IIS, obviously; I'm just trying to get my application running!)