Sysinternals Autoruns says that I have 8 instances of the Dropbox shell extension being loaded at startup, via the registry key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers
There is no apparent difference in the invocations -- they all run
c:\users\myUserName\appdata\roaming\dropbox\bin\dropboxext64.22.0.dll
But if I check the registry, they are each invoked with a different GUID and are named "DropBoxExt1 Class", "DropBoxExt2 Class", etc. There doesn't seem to be any parameter passed differently to the different instances.
I am on Windows 7 64-bit. Can I safely remove all but one of them?