Quickest fix: Windows - Taskbar Has Disappeared from the Desktop
- Press Alt + Ctrl + Del => choose Task Manager
- find the Windows explorer process,
- Restart it.
PS: If you use a remote desktop, Press Alt + Ctrl + End instead. It's actually not a fix; it's only a workaround. Anyway, we cannot expect there to be a perfect fix for that. Microsft just sucks.