3 possible ways.

1) Using the Add_in manager under the Tools menu
2) saving a file in the default xlstart folder
3) saving the file under the alternative xlstart folder

each of these can easily be checked...

theer is another way, but its more complex and is for
using component objects - and I suspect a bit techy for
this answer.

As a default, there's a file called Personal.xls in the
xlstart foldeer where you can save your code. This file
is hidden when opened in Excel...look under the Windows
menu. If there is a hidden file the unhide menu item will
be enabled.


HTH

Patrick Molloy
Microsoft Excel MVP

-----Original Message-----
Hi

When I open an Excel file, some "add-in" is downloaded
and installed in my
excel file. (Please reference to the pic.)
I want to know how they do that and where can I find
those downloaded
materials in my computer?(I want to change some coding
in it).

Thank you
!