Preview files from Windows Explorer in Windows 7

One of the most useful and much improved feature in Windows 7 is the Preview pane in Windows Explorer. The Preview pane helps you to preview images, videos (all files types that Windows Media Player supports), webpage files, text files (created in Notepad, WordPad), PDF files (when Adobe Acrobat Reader is installed), Microsoft Office files (when Microsoft Office is installed) without opening the respective applications. You may view the Preview Pane by pressing Alt and P keys from the keyboard.

You may also view the Preview pane by:
Clicking Show the Preview pane button from the top right part of the window.
Or
Clicking Organize button, hovering the mouse over Layout and then clicking Preview pane.

Note:
You may not be able to edit the changes to text file's from the Preview pane. However, you can copy the text from the text files from the Preview pane.
You may resize the Preview pane.
You may show/hide the Preview pane.