Windows 7 offers several ways to manage you desktop windows, such as : dragging the window to the top of screen will maximize it....etc. To disable this feature:
- Click on Start > Run.
- Type regedit and press Enter.
- Expand HKEY_CURRENT_USER\Control Panel\Desktop
- Locate WindowArrangementActive and set it 0
- Close the registry editor and restart your system for the modifications to be applied.