Sharepoint is not supported on Windows Home Server, by either the Sharepoint or Windows Home Server teams. There is a (somewhat old) set of installation instructions still available, I believe, but I don't have the link handy. Do a search here in the Windows Home Server forums and you may be able to find it...
As for your default web site, the simplest method is probably going to be server reinstallation. See
this FAQ for a (sketchy) description of the process, the caveats, etc.
I'm not on the WHS team, I just post a lot. :)