Hi Nick,

What do you mean by "several", and by "loading"?

Note that the Add-ins Manager dialog will only "list" in the dialog the
first 10 add-ins entered in the Add-in Manager key of the Registry, according
to their respective "index" in the Add-ins collection. (the order they were
added via the Add-ins Manager dialog) This does not include the (Default)
entry. The "installed" (as in Open) add-ins will be found in the Options key.

You can have more than 10 from the Add-in Manager key "loaded" (as in
"Open"), but if you uninstall any = to the 11th entry, they won't appear in
the list when Excel is reopened. They will still be listed in the Registry
key, but the Add-ins Manager seems to be limited to listing only the first 10
added to the collection.

When an add-in is checked in the dialog, it moves from the Add-in Manager
key to the Options key after Excel closes. The Options key enumerates them
like this: OPEN, OPEN1, OPEN2, ..and so on. Clearing the checkbox moves the
add-in back to the Add-in Manager key after Excel closes.

While Excel is running, checking/unchecking items listed in the dialog
respectively installs/uninstalls the selected add-in, but the Registry won't
update until you close the Excel session. This means all installed add-ins
will appear in the dialog when Excel reopens because they're listed in the
Options key. It doesn't matter what their index is in the Add-ins collection.

HTH
Regards,
Garry