It is explained in that thread which I linked to.
quote:
1) Install version 1.2 (to add the correct values to the registry)
2) after that, unregister the OLD DLL
3) unzip the version 2.0 DLL and replace the old DLL with this new DLL you just unzipped.
4) register this (new) DLL again...
Registering a DLL is done by going to
Start > Run and entering this in the command prompt:
regsvr32 "c:\program files\messenger plus!3\plugins\plehfilesharingvb.dll"
Unregistering a DLL is done by going to
Start > Run and entering this in the command prompt:
regsvr32 /u "c:\program files\messenger plus!3\plugins\plehfilesharingvb.dll"
(of course, mind the path, it may be different in your case)