You could go into startup and uncheck Dell Quickset. That may get rid of the tray icon.
Go to start , run then type msconfig then click ok. Click on the startup button.
Check the list for DellQuickSet and uncheck it hit ok and apply. Then restart
your system. A box will come up telling you about selective startup.
Put a check mark in the box that says Don`t show this message again
See if the icon is gone Good luck.