Shoutbox

tbh, the OSA thing (shown in the screenshot) is the most annoying thing of Office and is the first thing that I delete when I install Office.

osa.exe, osa9.exe, or other equivalents (depending on your MS Office version) is a small "tool" which loads common used MS Office components into the memory to help speed up the launch of Office programs. Most people claim there's no difference with or without it. It isn't required anyways, so in short: it is an annoying resource hog that you can safely delete.