Apparently there’s a hidden way of cleanly restarting Windows Explorer (explorer.exe) in Windows (ever since Xp) without killing it via Task Manager.
This can be quite useful in case of weird bugs or when one simply needs a way to restart the explorer.exe process in a non-intrusive way.
To do this, hold down CTRL and SHIFT while right-clicking on the transparent area or the small right arrow button in the Start Menu. This will open up a hidden menu. Click Exit Explorer to close Windows Explorer.
After the taskbar is gone, press CTRL+ALT+DEL and open up Taks Manager.
Here, select File > New Task (Run…) to open up the Run dialog and type in explorer.exe to re-start Windows Explorer.
All your open windows should be as you left them.