Prior to Windows Vista:
  1. Right Click on the Desktop. 
  2. Select Properties. 
  3. Select the Settings Tab. 
  4. Click Advanced. 
  5. Set the DPI settings to Normal.

Windows Vista:

  1. Open Personalization by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, and then clicking Personalization.
  2. In the left pane, click Adjust font size (DPI).   If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
  3. In the DPI Scaling dialog box, change the setting to Default.
 
Windows 7:
  1. Open Personalization by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, and then clicking Personalization.
  2. In the left pane, click Display in the bottom left.   If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
  3. In the DPI Scaling dialog box, change the setting to Smaller.