One of the things about the newer versions of Windows is that you can snap windows automatically to size by approaching an edge of the screen. With something as old as XP, for instance, you would have had to drag the window here, and repositioned the top, bottom, or side of the window to the extreme end you wanted it at. In addition, you can find out how to do this without needing to call the Windows 8 tech support phone number.
This is called the Aero Seek, which can also be introduced to older Windows versions like XP using third party software. If not, all you need to do is move the mouse to the top or the bottom of the window that you want to maximize in the vertical or horizontal direction. It has to be the edge and not just the title bar, if you are going to be resizing at the top. Pay attention to the pointer, because when you have it where it should be, the cursor would turn into a double-sided arrow. This is when you click and drag to resize.
Drag until you get the cursor to the edge of the screen, and the edge of the window will follow. If you are going to stretch the bottom of the window, then drag this to the bottom of the screen and let go only when you reach the end. In Windows 7 and 8, you will see an animation before you touch the edge, at which point you can let go and the window will get stretched to that end. This is called the Aero Seek, and as a feature it is absent in the older versions of Windows. Remember that this does not resize the window in both direction but only one, so if it is stretching vertically, the horizontal dimensions will remain the same.
Since it stays the same width afterwards, you can drag the title bar to effectively slide it to whichever side you wish. The window can be restored to previous size by double clicking the title bar. Alternatively, you can use the Windows + Down arrow key combo.
These are some of the things you really do not need to call the Windows 8 tech support phone number for. Many such features are explained in the Help menu, so you just need to read through that or simply search and find what you are looking for.