To protect cells from further editing, the Protected check box must be checked on the Format - Cells - Cell Protection tab page or on the Format Cells context menu.
Unprotected cells or cell ranges can be set up on a protected sheet by using the Tools - Protect Sheet and Format - Cells - Cell Protection menus:
Select the cells that will be unprotected
Select Format - Cells - Cell Protection. Unmark the Protected box and click OK.
On the Tools - Protect Sheet menu, activate protection for the sheet. Effective immediately, only the cell range you selected in step 1 can be edited.
To later change an unprotected area to a protected area, select the range. Next, on the Format - Cells - Cell Protection tab page, check the Protected box. Finally, choose the Tools - Protect Sheet menu. The previously editable range is now protected.
Sheet protection also affects the context menu of the sheet tabs at the bottom of the screen. The Delete and Rename commands cannot be selected.
If a sheet is protected, you will not be able to modify or delete any Cell Styles.
A protected sheet or cell range can no longer be modified until this protection is disabled. To disable the protection, choose the Tools - Protect Sheet command. If no password was set, the sheet protection is immediately disabled. If the sheet was password protected, the Remove Protection dialog opens, where you must enter the password.
Once saved, protected sheets can only be saved again by using the File - Save As command.
Allows you to enter a password to protect the sheet from unauthorized changes.
Complete protection of your work can be achieved by combining the options Tools - Protect Sheet and Tools - Protect Spreadsheet Structure, including password protection. To prohibit opening the document altogether, in the Save dialog mark the Save with password box before you click the Save button.