Is the Window border too fat for you? Would you like to put Windows on a diet? Loose up to 90% of your window weight. Better slim the window borders using a quick registry.
Open up Registry Editor and navigate to HKEY_CURRENT_USER, Control Panel, Desktop and WindowMetrics. Right click on PaddedBorderWidth and select Modify. Enter a value of any negative number up to 0. A value of 0 will produce no padding while a value of -300 will produce a very fat border. The default value is -60.
Click OK and reboot your PC.