1. Open Excel 2003 by clicking on the 'Start' button, then 'All Programs,' 'Microsoft Office' and 'Microsoft Office Excel 2003.'
2. Click 'Help' on the main menu, then select Detect and Repair. The Detect and Repair dialog box is displayed on your screen. You may be prompted to select an installation source. If so, browse to the location of your Microsoft Office installation files or insert the installation disc.
3. Choose if you want to restore your shortcuts or discard any customized settings by selecting the appropriate check boxes.
4. Click 'Start' to begin the Detect and Repair process. A Windows Installer window will appear, indicating the process has begun.
5. Allow the process to run. The program will prompt you when Detect and Repair has completed. Click 'OK' to return to Excel 2003.