I would like to add in my two cents (pence?) about a relatively inexpensive, web-downloadable program that I have been using to prepare for FAA written exams. I used it for my private pilot and instrument fixed-wing exams in 2000 and 2002, and am currently using it to study for my helicopter commercial one. It seems to be quite a bit less $ compared to the competition... I've been very happy with its functionality and features.
http://www.dauntless-soft.com/
As I recall it's about a 13Mb download.
good luck,
Dave Blevins