Taskbar glitches when alt-tabbing

While this isn't a serious problem, it's definitely a hell of an annoyance. When I alt-tab from several full-screen games, such as League of Legends, this is the result, sometimes it differs. In the image below, you can clearly see that something's wrong with the taskbar. I would also like to tell you, that when I hover the cursor on the taskbar, they return to normal.

When the taskbar is in its normal state, the search bar is there, correct?

You said:

When the taskbar is in its normal state, the search bar is there, correct?

No, it isn't, this is the normal taskbar
.

Killing and restarting explorer.exe should fix that. Just open task manager, kill explorer.exe and restart it (file -> run new task -> explorer.exe).

Appears to be random occurrence for me, I've had it happen once so far when alt tabbing out of Dota 2.