Just a bit more information on the (possible) cause and fix for the previous problem.
(1) When Control Panel "add/remove software" is used with visual
Studio Express or Visual studio
8.0 then the following message appears:
"... problem has been encountered while loading the setup components visual studio"
(2) When setup.exe is run form the disk (or ISO disk) then the following message (eventually) appears:
(drive letter):\vs_setup.msi could not be opened
Installing Visual Studio Express over Visual Studio 8
As described in previous post ie:
(1) Rename the Visual Studio directories to something else (ie. add REMOVE to the folder name)
(2) rename the following Register entry using REGEDIT (use with care!)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\8.0 (ie. change \8.0 to \8.0REMOVE)
(3) Download the Windows Install Clean Up utility at: http://support.microsoft.com/default.aspx/kb/290301
Use this software to 'clean up' anything with Visual Studio in the name.
(4) Reinstall the Visual Studio software
Worked for me! And that was after 2 days of trying everything else from loading with Virtual disks to getting fresh copies of the software.