Disable Aero Snap in Windows 7
Windows 7’s new ability to move and resize windows, in one movement can be great, however if you do not like this feature, use the below steps to disable it
To  Disable Aero:

  • Launch Control Panel,
  • Click Ease of Access,
  • Select either “Change how your mouse works” or “Change how your keyboard works”.
  • Browse down to the “Make it easier to manage windows” section,
  • TICK “Prevent windows from being automatically arranged when moved to the edge of the screen”
  • Click OK