Set Default Mail Program [to PMMail]

I want to add my mail program PMMail
to Control Panel - Internet Connection - Progams - Mail

All that the drop down arrow produces is a list of MS
programs, but no way to type anything in.

I have set PMMail to check it is the default, but whenever
I go to "send link" in Firefox it brings up #$%%#$ Outlook with Word as the editor.

I see that my wife has got Eudora in the list of programs
on her machine, but she can't remember how she did it.

Cheers,

Tom