If someone confirm ordering is working well, I think I'll be tempted to buy all the windows scenario, the wrapper seems work very well.
I found back the pdf that was given free at front page of the site, so it's hardly illegal and it won't hurt anything, but it will allow you start all the scenario already installed or that you download and install. But you won't be able to finish them until you order and get the codes for each scenario. You will need follow the procedure explained to reset the serial number to your new serial number.
So here an extract of the pdf given for free, PC version, a gift from the guy who don't answer fast to emails and is in charge of the thing but doesn't really own the copyrights (well I suspect it's not entirely right but well):
The serial number of your copy is 13706024 Your registration code is 7995820
you will have to reset the serial number of your copy so it matches the one listed above. To do this enter your verification code 410 instead of your registration code and it will allow you to RESET your serial number so it matches the one listed above.
1) Your scenario registration name is: MEIERS
2) Your registration number for Prelude to Pestilence is: 2846681
And this will also include the complete first scenario: City of Bywater.
To discover the game I strongly suggest play first City of Bywater. It's good stuff and much better to discover the special mechanisms, interface, first tricks and rules. Then you'll be ready for the grand adventure with first scenario of The Swords Lands trilogy, Trouble in the Sword Lands. But caution if you reach the code protection it could be hard to resist buy it.
For all scenario there's a really fairly large part to play before the registration code. Often scenario allow a lot of non linearity so if you reach the code you can try go back find more to do.
I suggest keep notes, each time there's text, information, dialogs, you can store it in the diary, but the diary is a pain to use, so you can also copy and paste the text and manage the diary yourself, really advised if your memory isn't top class, and anyway you could not really notice some important information.
If you want jump on the best you could also start with the second scenario of The Swords Lands trilogy, in my opinion the best of all and a quite impressive piece of RPG. If I remember well there's an introduction allowing choose a new party or one coming from previous scenario, choose a new party to get more information during first parts. You can create characters at level you want so it's possible despite the level requirement of this scenario.