Purchasing ebooks

[JD]

I bought Windows XP Inside Out (a Microsoft Press book) from a bookstore and
it included an ebook on a CD, which I've successfully installed on my
computer.
I like the idea of ebooks and would like to purchase some for download. My
question is, do I need to install a "reader" for this purpose?
I noticed on the MS site something called a Microsoft ebook Reader. May I
assume that I already have it (from the above-mentioned CD) or should I
download it? Do ebooks come in different "formats"?
If anyone has experience with purchasing ebooks, I'd appreciate some advice
on how to proceed.

 

[Mark L. Ferguson]

Online Books Page: http://onlinebooks.library.upenn.edu/
http://www.ebooklocator.com/

 

[JD]

OK. I've learned that MS Reader is but one of various ebook formats.
Amazon.com offers to download the Reader.
If I've successfully installed the Windows XP Inside Out ebook on my
computer, should I assume that the reader has been installed already? If so,
how can I verify that? The install from the CD created an All Programs
folder called Microsoft Press, containing a link to the above-noted ebook. I
don't see any file called Reader in the Microsfot Press folder in the
Program Files folder.
I'm also unclear on whether the MS Reader is only for "tablet PCs."