I just reinstalled Windows 7. When I installed Office 2010 I deselected some components to save disk space. Now, I can't open xlsm files. I would like to know which components in the Office installation will allow me to open xlsm files.
UPDATE 2: This turned out to be a permission issue. The Administrator group had ownership of the folder. I set my user name as owner and everything worked fine.
UPDATE 1: I just took another look at things and I'm pretty sure my problem is related to Windows 7 permissions. I can't even copy and paste the file due to permission issues.
The error message I get when I try to open the file is: Excel cannot open the file filename.xlsm because the format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.