From CoolPDF Software:

It’s a pity that a PDF reader isn’t included when Windows 7 is released. However, you can download and install a light-weight yet powerful PDF Viewer to serve as part of the operating system to view, print, and convert PDF. Zoom in and Zoom out to any size. Support zoom-in and zoom-out PDF pages to any PDF page to any size of your choice. Rotate PDF page clockwise and anticlockwise. PDF page can be viewed in different angles thanks to the fast rotation algorithm.