windows 10 how to disable "win" key without using the keyboard

The problem is probably hardware. It's possible to disable this key, but this will cause some difficulties with useful key-combinations that use it.

To disable the Win key:

• Run regedit
• Navigate to this key:
  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
• Right-click on an empty spot on the right "New | DWORD (32-bit) Value" and name it NoWinKeys
• Double-click the NoWinKeys item and change its value to 1
• The change will become effective after restart.

Additional methods may be found in the article
How to disable the Windows Key in Windows 10 [FULL GUIDE].