I would check for malware first. Do a complete scan with your AV app, then install MalwareBytes anti-malware and run a complete scan.
I have an Icon repair batch file that might help. Paste the lines below into Notepad, save as a .bat file to your desktop and run it:
@echo off
cls
echo The Explorer process must be killed to delete the Icon DB.
echo Please SAVE ALL OPEN WORK before continuing
pause
taskkill /IM explorer.exe /F
echo Attempting to delete Icon DB...
If exist %userprofile%\AppData\Local\IconCache.db goto delID
echo Previous Icon DB not found...trying to build a new one
goto :main
:delID
cd /d %userprofile%\AppData\Local
del IconCache.db /a
pause
echo Icon DB has been successfully deleted
goto main
:main
echo Windows 7 must be restarted to rebuild the Icon DB.
echo Restart now? (Y/N):
set /p choice=
If %choice% == y goto end
echo Restart aborted...please close this window
explorer.exe
:end
shutdown /r /t 0
exit
Don't know if this will fix your problem, but it did mine.