If after signing out, restarting you still see black squares.
1) If you haven't backed up the registry keys prior to modifying them
2) If you haven't go a system restore point or created a system restore point then you will have to manually revert everything you did.
[NOTE]However the instructions are not exhaustive and without knowing exactly what you did I cannot give you step by step instructions. The instructions below are only indicative of where the shortcut overlay is found.[/NOTE]
To revert:
1) Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Icons
2) double click on "29" in the right hand pane to change
3) and type in or copy %windir%\System32\shell32.dll,-16769
4) Press enter, close the registry editor and restart / sign out
If you're using windows 10.
1) HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.Ink\ShellNew\
2) Double click IconPath
3) Type in / paste %SystemRoot%\system32\shell32.dll,-16769
4) %SystemRoot%\system32\shell32.dll,-16769
It goes to show why people who don't know what they are doing shouldn't be messing with the registry in the first place :winktongue:.
Also can you link the tutorial here, in this thread after joining as I'm rather curious to see what may have gone wrong for you and plus I don't recall seeing any such tutorial however I may have missed it.