The new Windows 8 Consumer preview has many new features when compared to Windows 7 and one of the most prominent one is the Windows Explorer along with the start screen. The new Windows explorer sports a ribbon UI similar to Office 2010 and ha almost all functions and features inside the tabs. While in many ways the new UI looks better and is easy to use, many users of Windows 7 and previous versions of Windows might take time to get used to it. We have covered in detail on using the Windows Explorer on this blog. In case you want to disable the explorer UI permanently, you can try this free tool- Ribbon Disabler.
Once you disable it, you need to log off or restart the explorer to make the changes into effect. This will disable the ribbon UI in Windows Explorer only and the UI in Paint and WordPad will remain the same.
Currently this tool only supports 64 bit versions, but the author has said that work is on for the 32 bit version.