How to Secure Excel Data

1. Turn on your computer, open Excel, and find the spreadsheet that you need to secure.
2. Click on 'Tools' in the toolbar and then select 'Protection'.
3. Now you have several options on how to protect the spreadsheet. If you have a single sheet, then choose 'Protect Sheet'. If you have several tabs on the spreadsheet then select 'Protect Workbook'. Finally, if you want the recipients to be able to alter data, choose 'Allow users to edit ranges'. In this example you should choose 'Protect Sheet'.
4. When the Protect Sheet windows opened, type in a password in the password box, then check the appropriate boxes for the options that you need for the spreadsheet. Normally if you are protecting a sheet from being altered you should only check 'Select locked cells' and 'Select unlocked cells'. Click 'OK' to continue.
5. Save the spreadsheet, and if you want extra protection simply choose 'Save as', then click 'Tools' and then 'General Options'. This will open a Save Options window where you can add an additional password and make the document 'Read-Only' as well.
6. Once you have entered the password and selected the 'Read-Only' box, click 'OK' and then 'Save'.