http//:localhost/MOD11VB HTTP/1.1 500 Server Error

[M Skabialka]

I installed Visual Studio Beta 2005 but setting up the SQL server was so
complex I uninstalled it and put Visual Studio 2003 Academic on. I am
totally new to Visual Studio and trying to teach myself from books and
online classes.

Now, whenever I try to open .sln files (eg MOD11VB.sln) from the online
classes I get these messages:

The Web server reported the following error when attempting to create or
open the Web project located at the following URL:
'http//:localhost/MOD11VB' 'HTTP/1.1 500 Server Error'.

I hit OK, then it says:
'Solution C:\..........\MOD11VB.sln' and its projects must be converted to
the formats used by this version of Visual Studio .NET.
If you choose to convert this solution, all of its projects will be
converted as well... etc

I choose No and it closes, I choose Yes and in the Solution Explorer it says
MOD11VB (unavailable)
The project cannot be found.

This happens to any .sln I have from any source, like sample apps, etc.

Also, I don't seem to have http//:localhost set up. Where or how is this
done? I installed MSDE and it says it is running. IIS seems to be running
in Services.

I am completely lost here....

Any help will be deeply appreciated!

Thanks,
Mich