This does not get rid of the tray icon. This only gets rid of the icon in My Computer. You should be able to right-click on the tray icon and disable that version of scout from there.

Click Start > Run, and type:
regsvr32 /u "%commonprogramfiles%\Ahead\Lib\MediaLibraryNSE.dll"

To undo (put it back) :
regsvr32 "%commonprogramfiles%\Ahead\Lib\MediaLibraryNSE.dll"

This will not cause any harm.

A wiki page has been created, which contains multiple fun DLL registrations, including this one.