1, open Excel 2010, select any cell, right mouse button, open menu, select Format Cells command.
2, switch to the "Protection" tab, where we can see by default the "Locked" checkbox is checked, that is, once the worksheet is locked, all cells are locked.
3, press CTRL + A shortcut key to select all the cells, and then right-click the "Format cells", switch to the "Protection" tab, the "lock" before the small box tick, click OK to save the settings.
4. Select the cells you want to protect, check the Lock checkbox, switch to the Review tab, and click the Protect Sheet button in the change group.
5, pop-up "Protect Sheet" dialog box, in the Allow all users of this worksheet in the list box can choose to allow users to do what, generally retain the default settings.
6, here we can also set unlock lock when prompted to enter a password, simply remove the worksheet protection using the Password text box to type the password can be set.