Protecting Worksheets

Sometimes you may have a need to prevent changes to information in a particular worksheet in your workbook. For instance, you may want to send a worksheet to others for their review, but you don't want them changing the information or formulas in the worksheet.

Excel makes it very easy to protect one or more worksheets in any of your workbooks. You can do this by first specifying which cells in the worksheet should be protected, and then locking the worksheet.

Protection of your formulas or data is done on a cell-by-cell basis. This may seem odd, but it can be very handy. What it means is that you can protect all the cells in a worksheet, but leave the user input cells unprotected. When a user loads the worksheet, they can make changes to the user input values, see the calculations based on them, and get the information they need. The benefit to you is that you don't need to worry about users deleting information or changing formulas by mistake.

By default, cells are locked, pending your application of protection to the entire worksheet. What this means is that even though cells are locked, users can still change the cells unless you protect the worksheet, as described shortly.

If you want to change the condition of a particular cell so that it is not locked, you do so in this manner:

1. Select the cell (or cells) you want to change.
2. Choose Cells from the Format menu. Excel displays the Format Cells dialog box.
3. Make sure the Protection tab is selected. (Click here to see a related figure.)
4. Set the Locked check box to reflect how you want the selected cells treated when you protect the worksheet.
5. Set the Hidden check box to indicate whether the formula in a cell should be hidden from view when the worksheet is protected.
6. Click on OK.

Once you have specified how you want the individual cells treated, you still need to protect the worksheet as a whole by locking it. This step can be viewed as a way to "turn the key" in the locks you put in place for each cell.

You do this by selecting the Protection option from the Tools menu. This displays a submenu from which you should select the Protect Sheet option. The result is the Protect Sheet dialog box. At the top of the dialog box you specify what should be protected. You have three choices:

• Contents. Enforces any protection you applied to individual cells, as described earlier.
• Objects. Ensures the user cannot change placement or attributes of any graphics or other objects used in your worksheet.
• Scenarios. Protects any scenario definitions you have created, as discussed in previous issues of ExcelTips.

At the bottom of the dialog box you can specify a password to be used for unlocking the worksheet. For maximum protection, you should use a password that is easy for you to remember, but would be difficult for others.

When you click your mouse on the OK button, what happens next depends on whether you specified a password. If you did not, the worksheet is immediately protected. If you did use a password you will see a dialog box asking you to again enter the password. This is a double-check to make sure you did not mistype the password the first time. When you click your mouse on OK in this dialog box, the worksheet is finally protected.