Bret,

I think you have to go to the registry and try looking for 2 keys:

HKEY_CLASSES_ROOT\.Tax\shell\open\command if this exists and has a value (like d:\tax97\32bit\Ttxper97.exe %1) then the system knows "how" to open it, but might fail when acutally attempted because the .exe can have been removed from the system.

If the first doesn't work look for HKEY_CLASSES_ROOT\.Tax\ and get the value that will give you another key to search for. For example HKEY_CLASSES_ROOT\.app\ gives a value of Visual.FoxPro.Application.6 which you have to lookup a second time as HKEY_CLASSES_ROOT\Visual.FoxPro.Application.6\shell\open\command

And I guess you need to check the WIN.INI [Extensions] section.

>Your class is a great tool and I appreciate your time. My question involves knowing ahead of your shell.execute() method whether a .TAP extension is valid and can be handled by the system. Post error processing is ok, but in this instance I would like to know that the extension can be handled before hand.