Microsoft uses Windows Update to distribute free updates that fix bugs and improve security in Excel. To receive these updates, either run Windows Update manually or turn on automatic updates to download and install Excel updates as Microsoft releases them. If you have an old version of Excel and want to use features added to the program in recent years, you need to re-buy the program.
Regular Excel Updates
Open Windows Update by pressing the "Windows" key, typing "Windows Update" (without quotes) and selecting it from the search results. Click "Change Settings" and check the box in the Microsoft Update section. Without this box selected, Windows Update checks only for system updates. If you receive an error message when you try to enable Microsoft Update, sign in to Windows with an administrator account and try again. To receive Excel updates as they come out, open the drop-down menu on the settings window, pick "Install Updates Automatically (Recommended)" and click "OK." If you prefer to look at each update before installing it, leave automatic updates turned off, click "OK" and run Windows Update any time you want to check for updates.
Free updates through Windows Update won't upgrade Excel to the latest version, such as from 2010 to 2013. Microsoft releases bug fixes and security patches for outdated versions of Excel, but if you want the latest features, you need to buy a new copy of the program or any version of the Office suite. Alternatively, subscribe to Office 365. With a subscription plan, you can download and use the latest versions of Excel and other Office applications, even after new versions come out.
Information in this article applies to Excel 2013 and 2010 on Windows 8.1, 8 and Windows 7. It might vary slightly or significantly with other versions.