Just Trains Only Products:

All manuals for Just Trains products can be found in your Start Menu.

Start Menu:

Start > All Programs > Just Trains > [PRODUCT NAME] > [Manual.pdf]. 

If you are unable to find this (Windows 8/8.1/10users) please navigate to C:\Program Files (x86)\Steam\SteamApps\common\RailWorks\Manuals\EN where you will find all Just Trains manuals under the relevant product title.

(XP Users: C:\Program Files\Steam\SteamApps\common\RailWorks\Manuals\EN)

Third Party Products:

Other developers tend to save their manuals in different locations. We suggest that you visit the developers website and go from there.