VS 2010's Productivity Power Tools's Tab Well on the Right Side

I once managed to position the tab well vertically on the right side of VS's GUI by tweaking the registry.

But I can't find out anymore how I did it. Please refresh my memory.

EDIT : Before having this recent interface (see answer), These were "hidden" option that needed to开发者_如何学JAVA be tweaked like described here

---

Tools, Options, Productivity Power Tools, Document Tab Well, Advanced Options