GooReader is an application that allows you to search, download and read books and magazines available on Google Books from the Windows desktop.
You can search by book name or by book ID and also use the Google Book search operator “subject:”. The results are color coded to indicate the availability of book previews, full books are no previews. Books which are available in full can be opened and read within GooReader. Simple controls to turn pages, zoom and rotate orientation of the books are available.
GooReader is nothing revolutionary. In fact, it’s pretty flawed. The software, for some weird reason, wouldn't return more than 40 results, which is silly. Worse is, the default value is set to just 10. You have click on the gear icon in the title bar to go into settings and manually push up the vale from 10. You can enter any value here but results will get cut off at 40.
You can’t even download the books in PDF. For that functionality you have to get the paid version. Using Google Books on your browser is still the best option.