I was used to Windows Forms and non-resizeable windows when I posted this question, so I did not understand how to make content ajustable to the window. However, now that I understand how to use margins and other properties that allow for "responsive" windows, I highly recommend not to use this method. Use margins and alignment instead.
I've been working with WPF.NET for quite a while now, but there is a problem that has been bugging me since I first started using it in Visual Studio. It seems that when I run my program, the windows shrinks by 10 pixels, in comparison to the designer display.
Here are some pictures to better explain my problem:
Designer mode display:

Actual window when ran:

This has only been occuring in WPF. It does not happen in Windows Forms. It has been happening in VS 2012 and VS 2013.
Is there any way to solve this?