Windows 10 star menu is being silly.

[motive]

if your start menu is acting up here's a few steps.

Start Menu & Button not working in Windows 10

Before you proceed, some of you may want to create a system restore point first, so that you can revert back, if you find that the results are not what you expected.

1] Run the following command in an elevated command prompt, to run the System File Checker.

sfc /scannow

Restart after the scan is over and see if it helped.

2] Repair Windows Image. Open an elevated CMD copy-paste the following and hit Enter

Dism /Online /Cleanup-Image /RestoreHealth

Restart after the scan is over and see if it helped.

3] Make Start full screen and back. Enable Tablet Mode and Start Screen and then go back. See if this toggling has helped.

4] Open an elevated PowerShell window.


NOTE: After the November Update, if you use this method to fix this problem using the Appx PowerShell cmdlet, it may break your Windows Store apps. So we recommend that you do not try it now.

Type the following and press Enter:
Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

To open an elevated PowerShell prompt, type PowerShell in taskbar Search, and in the result ?Windows Powershell? which appears, right-click and select Run as administrator.

5] Create a new user and see if it helps. To do this, open an elevated command prompt window, type the following and hit Enter:
net user username /add

Here username is your new user name. You will see a The command completed successfully message. Log into your new account and see if has resolved your issue.

NOTE: You may do this, to open a Command Prompt or Powershell window. Press Ctrl+Shift+Esc to open the Task Manager. Click on File menu > Run new task. To open a command prompt window, type cmd. To open a PowerShell prompt, type powershell. Remember to check the Create this task with administrative privileges check-box. Then hit Enter.

If Cortana or Taskbar search is not working, open Task Manager > File menu > Run new task. Type powershell and select the Create this task with administrative privileges check box and click OK.

Let us know if anything worked for you or if you have any suggestions to make for the benefit of others

 

[motive]

Stop cortana

also this may help is to stop Cortana.

Disclaimer: Please see WernerCD's answer for an improved method. This will break the search bar/Start search.

Open Task Manager and have it show More details. Right click on Cortana and select Open file location.

Now find the Cortana folder, right click it, and select Rename. I would recommend just adding ".bak" to the end of the folder name so you can find it easily if you want to restore it back to it's original status

If you attempt to rename, it will tell you that the folder is in use.

This is when you want to go back to Task Manager, right click on Cortana, and select End task.

Right after the task ends, switch back to the Folder In Use window and click Try Again. The folder should be renamed and the Cortana task will not start again.