Well, Plus! tries to delete everything it can but because of the nature of global hooking, I can never be sure that some files aren't locked, even if Messenger is not running anymore. However, the uninstaller does uninstall everything else so appart from a couple of "dead" files that will be deleted at the next startup, everything else is gone, which means that you really don't need o restart immediately except if you need the extra 2Mb of space
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