
Still in Task Manger, select File > New Task (Run.), type explorer.exe, and click OK. Open Task Manager, go to Processes tab, highlight explorer.exe, and click End Process. (This file is hidden, so it you don't see it, you will need to adjust your Windows Explorer settings to show hidden files.)

Open Windows Explorer, go to %userprofile%\AppData\Local, delete IconCache.db. Based on answer, here is a slightly faster procedure (no reboot) that worked for me:
