Here is the patch:
http://www.microsoft.com/games/trainsimulator/downloads.aspx
It's needed to play some of the addons like the huge PRR Eastern system.
You also might want to look into OpenRails.
http://www.openrails.org/
Keep in mind that neither one is even remotely creator-friendly like Trainz.
http://www.microsoft.com/games/trainsimulator/downloads.aspx
It's needed to play some of the addons like the huge PRR Eastern system.
You also might want to look into OpenRails.
http://www.openrails.org/
Keep in mind that neither one is even remotely creator-friendly like Trainz.