Cannot attach zip-files

I’ve got a user who is trying to send an email with an Excel file and a Winzip file attached to it. When she browses for the files, she can see all the Word and Excel files in the folder, but none of the Winzip files appear, and thus, she can’t attach them.
How can she attach a zip-file again?

Sounds like somehow the component in Windows that supports zip-files is not properly registered.

To correct this you can reregister the correct dll via;
Start-> Run; regsvr32 zipfldr.dll

In some cases you’ll need to restart your PC for changes to take affect.