I'm using Visual Studio 2005 SP1 on a Win2K SP4 system.  VS is set up
to use "web development settings ". I use VB.

If I create a new web application project, then close the project and
exit VS I can see many files, including a .sln and a .vbproj file.

I can double click on the .vbproj file to load it, or I can load VS
and from within VS open the .sln.  But if I double click on the .sln
from windows explorer I get the error message:

"The selected file is not a valid Visual Studio solution file" and an
OK box.  I've googled for this and all see are problems related to
loading .sln files from earlier versions of VS.  I've never use any
other version of VS, and earlier versions are not installed on this PC
other than the old VB6 IDE and related tools, which I don't believe
uses .sln files.   The .sln I'm attempting to load was created on
exactly the same version of VS only seconds earlier.

Any ideas as to what I have to do to fix this?   I have no problems on
my home PC which is almost the same version of Visual Studio, but
which is on XP Pro SP2.

I've poked around on my home PC, and identified the following
differences.  On my home PC (where I can double click on the .sln) I
have version 77626-009-0000007-41632 of the various components. I also
have SQL Server Analysis Services,SQL Server Integration Services and
SQL Server Reporting Services.

On my work PC, which has the problem, I have 77626-009-0000007-41628
of the components, but says nothing about SQL Server. Both machines
have SQL Server 2005, but my home PC has a lot more of the front-end
tools, and later versions of some of the files installed.

Both PCs report:

Microsoft Visual Studio 2005 Professional Edition - ENU Service Pack 1
(KB926601)
This service pack is for Microsoft Visual Studio 2005 Professional
Edition - ENU.

But it's possible that my home PC has a later Service Pack for SQL
Server 2005 and more front end tools than my work PC. I think I
installed SP2 for SQL Server 2005 at home, which I might not have done
at work.

Finally, on my home PC, the icon for the .sln file is a blue window,
the little figure of 8 VS logo and a number 8 in the top right
corner.   But on my work PC the icon is two little windows, the figure
of 8 logo but no number 8.

Any ideas?  I'm finding it a little odd.  I can load the .sln from
within Visual Studio on both my home and work PCs which makes me think
it's just a file association problem but what's it getting confused
with?