Locate your product key for Windows 10 or Windows 11. Depending on how you got your copy of Windows 10 or Windows 11, you'll need either a 25-character product key or a digital license to activate it.

Find operating system info in Windows 11. To find out which version of Windows your device is running, press the Windows logo key + R, type winver in the Open box, and then select OK. Here’s how to learn more: Select Start > Settings > System > About . Open About settings.

Fix connections to wireless displays or docks in Windows. Learn how to screen mirror or project content from one device to another.

If your purchase of Office or Microsoft 365 came with a product key, you enter your product key on one of the websites listed below for your product. After you enter your key, you can download and install Office, or you can renew your Microsoft 365 subscription. Tip: Get tech expertise with Business Assist.

The VLOOKUP and HLOOKUP functions, together with INDEX and MATCH,  are some of the most useful functions in Excel. Note: The Lookup Wizard feature is no longer available in Excel. Here's an example of how to use VLOOKUP. =VLOOKUP (B2,C2:E7,3,TRUE) In this example, B2 is the first argument —an element of data that the function needs to work.

1. Check your speaker output. 2. Run the audio troubleshooter. 3. Verify that all Windows Updates are installed. 4. Check your cables, plugs, jacks, volume, speaker, and headphone connections. 5. Check sound settings. 6. Fix your audio drivers. 7. Set your audio device as the default device. 8. Turn off audio enhancements. 9. Restart Audio Services

Get help and support, whether you're shopping now or need help with a past purchase. Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.

Select Start > All apps and search for the app in the list shown. Press and hold (or right-click) on the app, then select Uninstall. Uninstall in Settings. Select Start > Settings > Apps > Apps & features . Find the app you want to remove, select More > Uninstall.

Find your files in Windows 11 using one of these methods. Search from the taskbar: Type the name of a document (or a keyword from it) into the search box on the taskbar. You'll see results for documents across your PC and OneDrive.

If you can't find a file on your computer or you accidently modified or deleted a file, you can restore it from a backup (if you're using Windows backup) or you can try to restore it from a previous version.