The customer portal to access your downloads made directly from the ChrisTrains webshop is here. (Knowledgebase article here)
For purchases made through partner webshops (Simtogether - formerly Treinpunt, Aerosoft, JustTrains, Railtraction), please login to your account on the partner webshop site.
ChrisTrains does not have access to partner webshop customer databases.

Please first check the knowledgebase - it is searchable, and it has answers to common questions about product updates, re-downloading the products, current product version numbers, manuals, scenarios, driving and control questions, and other product support issues.

Click here for the master destination list for newer ChrisTrains products.

If you cannot find the answer in the knowledgebase, please submit a ticket via the helpdesk, making sure to choose the relevant category and product.

I get literally hundreds of emails a day about my products. You are more likely to get a reply using the helpdesk than a personal email.

Patches for various products can be found in the knowledgebase: Patches

I'm fairly active on the following forums if you want to see update topics and general discussions:
Railsim.nl (Dutch)      Simtogether.com (Dutch)      Dutchsims.nl (Dutch)      UKTrainSim (English)