Windows has always had the ability to make any window the topmost one ever since Windows 3.0. Once you make a window the topmost one, other overlapping windows will always show below that window in the Z-order. It is possible to make a window the topmost one programmatically but Microsoft felt that if this control was given to end users, then application developers would misuse it to make their programs always on top. Still, third party tools can easily use the Windows API function to change this. Let's look at two ways to make a window on top.
Always on Top tool for Windows (Alternative to PowerMenu)