Catastrophic Failure?! Yikes. So I tried to repair my installation. Boy did I try. I uninstalled Platform Builder, hoping it would set my VS2005 back to rights. No such luck. I tried uninstalling VS2005. I tried a particular tool which offers to remove any vestiges of a previous install. After way too much time, I continue geting messages asking me to "Please repair Visual Studio." You have no idea how much I want to repair.
I found the following advice at http://support.microsoft.com/
kb/904732 , titled "How to troubleshoot the installation of Visual Studio 2005"
"The computer where you install Visual Studio 2005 should never have had any beta or release candidate Visual Studio product installed. If any one or more of these products were installed, you should rebuild the computer to verify that these products have been removed. To rebuild the computer, reformat the hard disk, and then install the operating system again."
That's one way to uninstall software. They should have simply recommended that to uninstall the software, shut the machine off, back slowly away, and go buy a new computer.