Before you go on with the following methods, you should create a system restore point first, just in case any unwanted error happens. Relog into your account Re-logging to your desktop is one of the easiest workarounds for you to try. If your Start menu was only gone occasionally, you should go with this option.
Here is how you relog into your account: If the same problem keeps reoccurring, you may need to try other methods below. You can change the new local account to a Microsoft account and transfer your files and settings.
Reinstall video card and sound card drivers Many Windows users say that their video card driver and sound card driver are the culprit, especially after the latest Windows update, and quite a number of them got their Start menu back after they reinstall or update their video and sound card drivers to the recent correct version.
Here is what you can do to get your Start menu working like a charm again: Right-click your audio card driver and click Uninstall device. When prompted with the following notification, tick the box for Delete the driver software for this device and click Uninstall. Note that if you are a laptop users, you should go to the laptop manufacturer for the correct video driver, since drivers from chipset manufacturer or video card manufacturer might not include the customized features you need for you laptop.
Driver Easy will automatically recognize your system and find the correct drivers for your exact video card and audio card, and your variant of Windows 10, and it will download and install them correctly: Driver Easy will then scan your computer and detect any problem drivers. Even if you disable your other antivirus programs, Windows Defender is always there for you during that certain time range. So, no need to worry too much about temporarily turning antivirus off.
Uninstall Dropbox Many Windows users find that Dropbox somehow conflicted with the Start menu, making it impossible to use all the feature in the Start panel. If you have Dropbox installed, try to uninstall it from your system. It will check if the Start Menu and Cortana are installed correctly, and whether registry key permissions and database corruptions are in place and more stuff like these.
Install this troubleshooter and see if your problem can be fixed by it. If the problem remains, you should move on to the methods coming up next. Check and repair Windows files At times, your not working Start menu should be the result of corrupted system files. Luckily, you can easily get it fixed by running two built-in system tools.
Here is what you need to do: Wait for a while for the process to complete. If the result you see is the same with the screen shot above, your system files are all right, and you should move on and run another test. Still, it could take a while, wait with patience. Reinstall Cortana The reason why your Start menu and Cortana is not working could be that they are installed wrong, somehow. You can reinstall them to get the Start menu feature back.
Last but not least: If you want to know more information about refresh in Windows 10, here is a post for you. Share with your friends and families and help them with similar problems!