Just Trains Only Products:
All manuals for Just Trains products can be found in your 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.