Hello,

I recently had this same problem (I'm running Vista). The site below has a
registry fix pertaining to .zip files that helped me. After downloading and
installing the fix, you will need to restart your computer.

http://www.winhelponline.com/article...ows-Vista.html

--
John Mansfield
http://www.cellmatrix.net


"Steph" wrote:

I am trying to create an add-in using Excel 2007. When I renamed the xlsm
extension to xlsm.zip, I accidently tried to open the xlsm.zip file with
Notepad instead of double-clicking on the xlsm.zip folder. Now every Excel
xlsm file that I create and then add a .zip extension to appears as a Notepad
file instead of a Windows folder. As a result, I can't open an xlsm.zip
files. Would appreciate your help.

--
Steph