A:
Your LCD monitor must have a "VESA-compliant" mount on the back in order to attach it to most monitor arms. Not all monitors are so equipped, although most modern monitors have a 75mm or a 100mm VESA mount. Don't try to improvise by drilling holes in the back of a non-VESA monitor; there will be no internal structure to support the monitor's weight and you'll most likely end up with scrap...
You can sometimes find monitor arm vendors who will supply you with a non-VESA mounting option. Look at Flexor or Chief or Peerless models. Maybe even Ergotron.
Answered on 12/9/2009 by Bob (just Bob) from Los Gatos, CA