Home premium? Write Permissions have been restricted by Microsoft for anything in a Microsoft created folder such as program files and Program files (x86) and they have made it pretty difficult to fix as they did not include the full files for changing permissions in Win7 below Win7 Pro, it can be done but easier to do as below.
You really needed to Install run and patch Trainz as Administrator in Win7, that avoids the permissions problems you get if you install it in program files.
However, Right click the Trainz icon, Properties, Compatibility, Run this program as an administrator, apply should get things working.
You may find if this doesn't help you need to do this for all the Trainz executable files including the ones in the bin folder.
Ideally it should have been installed in it's own folder, say C:\N3V\Trainz or another drive or installed as administrator initially if in program files.
Administrator account has been crippled in Home Premium by the way, which is why you have to set in properties or specifically tell by right click run as administrator, each program you need run as Admin, even if you are running an Admin account, most annoying!
