You can rebuild the icon cache which is under %localappdata%\Microsoft\Windows\Explorer
Please follow these steps.
- Open Command Prompt (CMD) as administrator from the start menu.
 - Run 
taskkill /F /IM explorer.exeto stop explorer. - Run 
del %localappdata%\Microsoft\Windows\Explorer\iconcache*to delete the icon cache files. - Run 
start explorer.exeto start explorer and the icon cache should be rebuilt automatically.