To find out which version of Outlook is installed locally on your Windows computer, please follow these steps:

1. In Outlook, click on "File"
2. Click on "Office Account" (or "Help" and then "About Outlook" if you don't see "Office Account")
3. Under "Product Information", click on "About Outlook" to see your version and build number

If you need detailed information, please read this Microsoft Knowledge Base article.