Windows 7- sure is a nice OS. For your presentations quickly use this Screen Magnifier or Zoom feature: Win Key + '+' Key or '-' key. Use the 'Lens' (Ctrl+Alt+L) to Zoom with a Square View (Yes. this Square view is fixed size). Options settings: use mouse wheel / keyboard keys, etc. Point: Opening Magnifier is easy with short cut keys, but to close? Win Key + ESC Key. (This will not work when Google Talk installed and short cut is enabled! ).
From the tech stacks I climbed and learned