The frm file is basically the code module that contains the VBA code
associated with your userform. The frx file is a binary file that
contains the (descriptions of) the form itself, all the controls that
reside on the form, and other resources needed to create the form. VBA
expects that the frm and the frx files have the same name (the name of
the userform) and that they reside in the same directory. You can open
both the frm and frx files in Notepad or your favorite text editor to
see what's in them. The frm file is readable, and it just has the VBA
code (and a few directives) that you'd see in the VBA editor. The frx
file is binary and contains nothing that you can read.
Critically important. Without the frx file, there is no form.
Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)