After a while I noticed on my Win 7 x64 machine that the Offline Sync Overlay Icons had disappeared, from all my synced network folders.
So How could I easily tell which one was synced and what status it had
After googling a bit I found some articles that described the limitations of the # of overlay icons that a folder could have.
It seems Windows 7 can handle max. 11 overlays icons ?
Which are found in this place : HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\ Explorer\ShellIconOverlayIdentifiers
So after investigating I found out that Skype / Dropbox / Skydrive and Gdrive had taken in the most part if it.
To resolve it you might want to delete some, like this one : EnhancedStorageShell and some more
To find out which icon is which :
Search the registry for the hex string inside the key’s value
1. Open the key inside the result (InProcServer32) and copy the value (the DLL path)
2. Create a new folder on the desktop
3. Right-click -> Properties -> Customize -> Change Icon
4. Paste the DLL path into the address field and hit Enter
See which icon(s) are displayed.
Or live with it as it is and get the icon and status form the detailed explorer pane.