After start up, the taskbar disappears

After one of my users starts up his laptop the taskbar shows, then after about one minute the taskbar disappears and you can not click any of the desktop icons.

The task bar is DEFINITELY not hidden, it is NOT dragged out of view,

The only ways I have seen to temporary resolve this is to

1. Restart the computer (takes a 1 or 2 restarts)
2. Hit Ctrl+Shift+Esc to launch the Task manager, Kill Explorer.exe, then launch Explorer.exe.

Any thoughts on a way to fix this.

thanks

 

They have a corded mouse connected, even hitting the start button on the keyboard will not bring up the start menu.

The cursor will move around, it just seems like everything is frozen, then after I kill explorer.exe and restart it all works fine.

It is definitely NOT the taskbar auto-hiding.

Also, I have done full virus and malware-bytes scans. I checked the startup tab of msconfig and I did not see anything out of the ordinary.