To password protect a file in Microsoft 2007 - ignore the logical “Protect Document” icon on the review pane. This is a shameless plug from Microsoft to try to get you to buy additional services.
Instead, click the Office Button > Prepare > Encrypt Document
Then just type your Password where asked. You will be asked to verify. The document/workbook/PowerPoint will now be Password protected.
If you liked my post, feel free to subscribe to my rss feeds
BlogoSquare