I'm hoping somebody here can point me in the right direction. I work at a
small nonprofit where we manage our IT needs with the equivalent know-how of
chewing gum and duct tape.

A few weeks ago, someone in our office encrypted a few Excel spreadsheets
and folders using the right-click, Properties, Advanced. Encrypt function.
Now nobody, including that person, knows how to un-encrypt them. I've been
tasked with trying to figure it out.

Any suggestions are greatly appreciated.