Open Command Prompt as administrator and copy-paste the following commands followed by hitting the enter key:
cd /d %userprofile%\AppData\Local\Microsoft\Windows\Explorer
del iconcache*
Reboot.
If the above doesn't help then:
Open File Explorer and go to C:\Users[YourUsername]\AppData\Local\Microsoft\Windows\Explorer
Delete all files that start with "thumbcache".
Reboot.
Open the Command Prompt as an administrator.
Type sfc /scannow and press Enter.