[dba-Tech] ASP nightmare

I run a test bed IIS 6 server for a number of client systems using
everything from ColdFusion to PHP and from standard HTML to ASP.Net. A
number of sites run straight ASP. (The Database Advisors web site
http://www.databaseadvisors.com is one example.)

Early last week, seeing the Server is 2003, an upgrade fro fso.objects was
recommended via MS. The upload and install was performed and everything ran
fine....NOT! 

>From then on ASP applications work fail. With the error:

Active Server Pages error 'ASP 0201' 
Invalid Default Script Language 
The default script language specified for this application is invalid.  

There is nothing wrong with the IIS configuration, the security... to that
end, the IIS server has been removed completely and replaced, twice. ASP is
also completely replaced within this process.

There is obviously nothing changed with IIS or ASP but the Server 2003 has
had some subtle changes made to either the directory/file permissions or to
some entry in the registry. A week later...no joy.

Has anyone had similar problems and found a solution. (Sorry no current
system backups... so the next step is a dreaded system re-install.)

MTIA
Jim