Hi pmax,

There's probably a lot of different ways to handle this issue, but it really
boils down to personal preference as to what works best, by scenario.
Tracking this properly is the key. Here's some suggestions:

1. You can use the SaveSetting & GetSetting VBA functions to store the info
in the Registry. This allows you to update the info in the registry when your
add-in starts, or read the current info to test running version against
previous running version. See VBA Help for how to use these functions.

2. You can do something similar to the above using an .INI type text file
instead of using the registry. This requires custom functions and a small
number of API function declarations. -Not as easy as suggestion #1.

3. You could identify your .xla file by including the "version" in the
filename, possibly. Example: myaddin_1.1.1.xla where a "major.minor.build"
series is used to identify it. Most usually use something like
"myaddin1.0.xla". (The simpler, the better)

4. As suggested elsewhere in this thread, use an "About" form to display
the info to your user. It would also help you with user support by including
a control to display the user's OS and Excel version. The number of features
you could include with this form are not limited. Check out other software
"About" dialogs to get some ideas.

Good luck,
GS