You've labored on your spreadsheet and you need to make sure anyone you share it with doesn't inadvertently change cells that really should not be changed. Thankfully, Microsoft Excel 2016 and earlier versions let you lock cells to safeguard them from being modified on Windows 10. You can lock all of the cells inside a worksheet or specific cells, allowing some parts from the spreadsheet to be changed. Here's how to lock cells in Excel.

Editor's Note: This tutorial was written for Excel 2016, but still applies to modern versions of Excel.

How you can Lock All of the Cells within an Excel Worksheet

By default, when you protect a sheet or workbook, all the cells is going to be locked. This means they cannot be reformatted or deleted, and also the content inside them can't be edited. Automatically, the locked cells can be selected, however, you can change that within the protection options.

1. Navigate to the Review tab.

2. Click Protect Sheet. In the Protect Sheet window, enter your password that is required to unprotect the sheet (optional) and then any from the actions you need to allow users.

3. Click OK to protect the sheet.

Whenever you or other people attempts to edit any of the locked cells, this message will come up.

Cells can only be unlocked once the sheet is unprotected (by going to the Review tab again, choosing "Unprotect Sheet," and entering the password, if required).

How to Lock Specific Cells within an Excel Worksheet

There can be times when you want to lock certain cells from being changed but nonetheless allow users to adjust other cells in a worksheet. In our example, within an inventory list you may allow unit prices and stock quantities to be updated, but not the product IDs, names, or descriptions. As stated before, all cells are locked by default when you protect the sheet. However, you are able to specify whether a cell should be locked or unlocked within the cell's format properties.

1. Select all of the cells you don't want to be locked. These would be the cells that may be edited despite the sheet remains safe and secure.

2. Right-click on your selection, select Format Cells, and then click the Protection tab. (Alternatively, underneath the Home tab, click the expansion icon next to Alignment, and in the Format Cells window visit the Protection tab.)

3. Uncheck "Locked" (which is checked by default) and click OK.

4. Go to Review > Protect Sheet and hit Alright to protect the sheet. Any cells you didn't unlock under the Format Cells option (step 3 above) will be locked, while the unlocked cells will be editable.

Note that cell locking (or unlocking) won't take effect until you do step 4, protecting the sheet.

Protip: If you want to quickly lock or unlock cells that aren't alongside each other, you can use a keyboard shortcut. After selecting a cell or number of cells, use the Format Cells dialog as above to lock or unlock it. Then select your next cell(s) striking F4 to repeat your last action.