Click on a cell, or highlight a range that you want unprotected. Click on Format > Protection. Untick Locked and press OK. Now click on Tools > Protection > Protect Sheet. Leave the Protect Sheet panel and Password (optional) untouched (unless you want to set a password) - click OK. Type in any cell that is protected and a warning is issued. Only in the unlocked cell or range can data be added or taken away. Incidently, pressing the Tab key will cycle the cursor from unlocked cell to unlocked cell. I'm using excel97.