» Protecting Cells Containing Formulas in an Unprotected Sheet in Excel 2007

To protect cells containing Formulas in an unprotected sheet, use Data Validation:

Step 1: Selecting cells containing formulas:
Select Home - Find & Select (in Editing Group) - Formulas.
Or
1. Press F5.
2. Click Special, and then select the Formulas option.
3. Click OK.

Step 2: Data Validation:
1. Select Data - Data Validation (in Data Tools Group).
2. Select the Settings tab, and select Custom from the Allow dropdown list.
3. To protect formulas type in the Formula box ="", and then click OK.
Screenshot // Protecting Cells Containing Formulas in an Unprotected Sheet in Excel 2007