Windows

Microsft Magnifier is a screen magnifying program
distributedwith Windows It's available via the accessibility
control panel and allows the user to enlarge the screen
for more comfortable viewing. Though this software
is not intended to take the place of more fully featured
magnification programs such as ZoomText, it is intended
to provide temporary access to magnification functionality
for short term use.

Starting Magnifier
Click the Start Button on the Window taskbar at the bottom
of the screen.
Click on the AT Applications folder.
Click on the Magnifier icon.
(You can also press <CTRL> + <ALT> + <5> to start the program)

Magnifying
When you start Magnifier the screen will split into two parts. The top part
will be enlarged. An Option window will open allowing you to manipulate
the settings of the program.

Quitting Magnifier
Left click on Exit or press <ALT> + <F4>

mac users

With Zoom view you can magnify everything on screen making it larger and easier to see.
To enter zoom mode, first turn on the zoom by pressing Command Option 8.
Now, press Command Option + (Plus) or Command Option - (Minus)
to zoom in and out.