Train Simulator Classic is made by Dovetail Games (DTG) but is distributed through Steam, which is, according to Wikipedia, "a digital distribution, digital rights management, multiplayer and communications platform developed by Valve Corporation. [...] Steam provides the user with installation and automatic management of software across multiple computers". Steam acts as the store front for dozens of game publishers amd you can buy thousands of game titles throught the Steam store. Steams offers several other features but the store is what we're interested in today.
Before buying anything on Steam, you need to:
- download and install the Steam client from the Steam website; and
- create a free Steam account if you don't already have one. The license for any game you buy will be associated with that account. Needless to say, you should choose wisely your Steam name and create a strong password which you should keep very safe, because it is the key to all your games purchased on Steam.
To purchase Train Simulator Classic, you can either go directly to the Steam store, either via the Steam client or the Steam web site, and search for "Train Simulator Classic", or you can go to the convenient "Products" page on the official Train Simulator Classic website, browse to the product's page, then click on "Buy" or "Add to cart"... which brings you to the Steam store.
You'll notice that the "Products" page and the Steam store both offer a number of add-ons for Train Simulator Classic, but this is not interesting right now, as you must first buy Train Simulator Classic itself. More on add-ons (or DLC, for "downloadable content") in a different thread.
Once you've purchased Train Simulator Classic and the transaction is confirmed, after you have parted with a variable amount of money, which can be quite reasonable if you have waited for one of Steam's periodic sales (up to 75% at times, usually 50% around major holidays), you will see Train Simulator Classic added to your Steam library. You can now install it or re-install it on any computer by simply double-clicking it in the Steam client.
If, at any time, you get a new computer, you don't have to copy Train Simulator Classic over. You just need to install the Steam client on it, log in (hopefully you remember your password) and Steam will install all the games in your library.
If, for some reason, your local installation of Train Simulator Classic becomes corrupted and is giving you problems, Steam has a very simple functionality for verifying the local files and fixing or replacing them. No expertise needed on your part.
Also, and this will surprise old-timers, you don't have to go hunting for patches and updates. Steam takes care of that, even while you sleep or toil away at work, if you don't kill the Steam client.