QTTabBar is an extension that brings tab functionality to the Windows Explorer file browser. Began as a project by a Japanese developer known as Quizo, QTTabBar (which also goes by QT TabBar) added tabs to Window Explorer during the many years when Windows XP and Vista were the latest releases. For unknown reasons, Quizo dropped development on the extension before Windows 7, but it was picked up by a user known as "ShiningMasamune" (real name Paul Accisano), who has since made it compatible with Windows 7.
The version we tried out today is written by Mr. Accisano, who has made significant changes to the original program. The installation is easy -- launch the installation package and click through the steps. You can use this same package to uninstall the extension should you chose to remove it. Now launch Windows Explorer and play with your new tabs.
The first thing you'll notice is a nifty new toolbar. Hovering the cursor over icons tells you the function of each button. Window XP users may have to take an extra step to rearrange their toolbars from the View > Toolbars menu. To use tabs, click on the Clone This icon to clone your current window and make a new tab. Cloning is particularly useful when you have to manage multiple deep folders without having to open a large number of windows. The other icons do a variety of functions such as Close Window, Close Current Tab, and Close All Tabs in a specified order, and there's even a Search bar (normally missing in Windows XP).
If you are not afraid of diving into the muck, there are multiple options for customization such as setting shortcut keys and skins. QTTabBar also offers a variety of plug-ins that will increase the level of functionality. For casual users, the standard offerings are useful enough.
A word of warning: QTTabBar is still in beta development, so there may be small glitches or slowdowns when using daily. We didn't experience any problems with regular usage, but there was a minor slowdown -- after having 20 tabs open -- that quickly resolved itself. For a free download, QTTabBar is pretty handy tool, especially if you're not planning to update to Windows 8 right away.