Visual Studio 2012, Solution Explorer, left to right

I. I have been using visual Studio2012 as an open environment for project development, each time you open vs2012 and create a new project, Solution Explorer is on the left side, such as:

But in the evening when open VS2012, suddenly become so, "Solution Explorer" unexpectedly ran to the right, as shown:

Anyway, looking very awkward, very not accustomed to. Maybe it's because I've long been used to the "Solution Explorer" on the left.

Two. There are two solutions:
1. Click "Window"--> "Reset Window Layout (R)", as shown in figure:

The time has come to witness miracles, ah, ah ~ ~ ~ ~ The Solution Explorer window is still on the right, the original system Environment default Solution Explorer window is displayed on the right because I have been using VS2012, so I don't know if the other series vs is also default on the right. Had to use the 2nd plan.

2. Click "Solution Explorer" to hold and drag, drag its window to the left, but it is worth noting here, not just drag to the left. When you drag the window, there is a "homing prompt" prompt. Such as:

You must drag its window to this "homing cue box" so that it's done, and it's back to the original location.