That may be caused by a corrupt icon cache, try this fix.
Click the Start button, type cmd, and in the resulting list, right-click Command Prompt and select 'Run as administrator'.
Run this command and press Enter:
taskkill /f /im explorer.exe
Run this command and press Enter:
del /a /q "%localappdata%\IconCache.db"
Run this command and press Enter:
start explorer.exe
When the command completes, close Command Prompt and restart (not shut down) your PC.