How to Protect a Single Cell in Excel 2007

1. Click any cell in Excel, hold the 'Ctrl' key and press 'A' to select all cells. Alternatively, click the triangle at the top left of the worksheet, located just above the row numbers and to the left of the column letters.
2. Right-click any selected cell, and click 'Format Cells.'
3. Click the 'Protection' tab, uncheck 'Locked' and click 'OK.'
4. Click any cell to deselect all the other cells.
5. Right-click the single cell you wish to protect, and click 'Format Cells.'
6. Click the 'Protection' tab, check 'Locked' and click 'OK.'
7. Click the top 'Review' tab, and click 'Protect Sheet' in the 'Changes' group.
8. Enter a password in the 'Password to Unprotect Sheet' field of the 'Protect Sheet' dialog window, and click 'OK.'
9. Re-enter the password in the confirmation box and click 'OK.' That single cell is now protected. To unprotect it, click 'Unprotect Sheet' in the 'Changes' group of the 'Review' tab, enter the password and click 'OK.'