Can anybody help with this problem?

After ~ two years of using Visual Studio .NET Enterprise Architect 2003 with
no problems, I suddenly started getting the error message "MS development
environment has not been installed for the current user...".  I have VS2005
& SQL2005 installed, and have been using them side-by-side with no problem
until this week.  I have never had a VS beta installed.

To my knowledge, only two things have changed since I last used VS2003:
1) Latest round of MS patches
2) Installed the COM Interop shim from
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnoxpta/html/od
c_comshim.asp

Having searched google, I found many posts referring to betas, and all
references were over a year old.

I have tried searching for the various GUID's in HKEY_CLASSES_ROOT/Licenses
that various sites suggest one can delete to correct.  I have tried logging
in as a different user  (including as Administrator)   as some sites
suggested.

I have tried repair/reinstall,  which completes but still results in the not
installed error when launched.  Uninstall fails with the error message ""