Sometimes it is important to protect your Excel data.
When you have spent a lot of time working on an Excel spreadsheet it can be important to make sure that people don’t have the ability to edit that data in some situations. Maybe you’ve created important financial information or a statistical analysis of Excel that you want people to view but not edit. Knowing how to protect a spreadsheet with a password is a valuable tool to have in your software bag of tricks. Just for your knowledge, you can also protect a Microsoft Word document in a similar manner.
Here is a great tutorial from the good people at www.TeachUComp.com.