When I installed Blender in Ubuntu it created two entries in the Applications/Graphics menu. One is for full screen mode, the other is for windowed mode. However the windowed mode didn’t work for me. So I googled around and found the following solution:
Open System/Preferences/Main Menu in Ubuntu
Navigate to Graphics
Right click on Blender 3D modeller (windowed)
Select properties.
Write the followings to the command field: blender -w -p 10 100 1024 768
Close and enjoy.
You can change the -p parameter values the following way: -p x y w h
where x,y is the lower left corner of the window. In this case it is 5px from the left of the screen and 100px from the bottom.
w is the width, h is the height of the window