http://www.pprune.org/forums/showthr...t=exams+online
On the top of your screen is a search function; this was how I found the above for you. Keywords - exams online. Please use it and you will find a wealth of information.
You should also be aware that the PPL exams are the same for fixed wing (except for Principles of Flight) and you will also find a lot of useful knowledge on the Private Flying forum (from whence the link above came!)
Cheers
Whirls