Sorry, I fail to see why one would call it "not required" - I would venture a guess that most users consider a volume control important. Here's a screeny file with this add-on question:
If systray.exe is in fact in the system32 folder, why is CCleaner flagging this as a missing file? As can be seen in the screeny, it is there...
If an executive decision was made to delete it, why? Further, if it is a constant target for malware, etc.., why not check its integrity during the install, and if it changes later, give it the axe.