How to Convert Microsoft Excel 2003 to 2007

Using Microsoft Excel XP or Excel 2003
1. Open a Web browser window and navigate to the Microsoft Windows Update website. Follow the on-screen instructions to download and install all high-priority updates for your operating system version.
2. Navigate to the Microsoft Download Center page for the Microsoft Office Compatibility Pack. Click the 'Download' button and save the installer file to your computer.
3. Close all open Microsoft Office programs.
4. Double-click the icon of the installer file you downloaded previously. Follow the on-screen instructions to install the Office Compatibility Pack on your computer. The software allows you to save files to XLSX format using Excel XP or Excel 2003.
5. Open Microsoft Excel XP or Excel 2003.
6. Click the 'File' drop-down menu and select 'Open.'
7. Locate the XLS file you want to convert and double-click its icon.
8. Click the 'File' drop-down menu again and select 'Save As.'
9. Give the file a name and select a save location. Choose the 'Excel 2007' option from the 'Save as type' drop-down menu. Click 'Save' to convert the XLS file to XLSX format.
Using Microsoft Excel 2007
10. Open Microsoft Excel 2007.
11. Click the round 'Office' button in the top left corner of the window and select 'Open.'
12. Locate the XLS file you want to convert and double-click its icon.
13. Click the 'Office' button again and select 'Save As.'
14. Give the file a name and select a save location. Choose the 'Excel Workbook' option from the 'Save as type' drop-down menu. Click 'Save' to convert the XLS file to XLSX format.
Using Zamzar
15. Open a Web browser and log on to the Zamzar website.
16. Click 'Choose File' and select the XLS file you want to convert.
17. Select 'xlsx' from the 'Choose the format to convert to' drop-down menu.
18. Enter your email address in the adjacent field.
19. Click 'Convert.' Your file will be converted to XLSX format within minutes. Once finished, a download link will be sent to the email address you provided.