good for you it looks like windows 7 is the problem with a lot of people microsoft should have stayed with bloody xp they have totally screwed things up for us gamers
Yes Win7 is a bit odd when it comes to comparison with XP, it's a case of forgetting what worked in XP and adapting to the new system, nearly as much of a culture shock to some as when people moved from Dos / Windows 3.1 to Win95, it's different.
Result is it works perfectly here on Win 7, I dual boot XP and Win7 and Trainz performs far better in Win7.
If you are confident in your ability to avoid malware, trojans and virus's try knocking the UAC control down to bottom but one setting.
You need the latest Graphics drivers for your graphics card, do not use the one supplied by Microsoft which for Nvidia anyway does not have OpenGL drivers. Use the one from the card manufacturer. Probably the same for ATI.
Content Manager needs OpenGL it won't work without it, the Simulator however will run in either OpenGL or DirectX.
OpenGL drivers for Win7 were pretty useless initially (down to ATI and Nvidia) but are getting better with each driver update however DirectX seems to be fine.
You need to Install as Administrator, preferably not in Program Files. Win7 blocks write access to program files unless running as Administrator. I put all programs on a separate drive to avoid Win7 taking control!
If you haven't got one C:\Auran will do just as well for Trainz
You need to run the program as administrator.
You also need to run patches as Administrator with Antivirus and anything else that's running disabled and leave the PC alone for at least two hours, the patch can take up to 6 hours depending on your system specs ./ available space for expanding and caching files. I leave mine to patch overnight. Some find patching in safe mode is easier.
Ignore the progress bar it does not move much until near the end of the patching process. Trainz uses a large database to store details of all the assets and this seems to need updating when patching, which is why it takes a long time. Interrupting this process will invariably need you to reinstall from scratch.
After patching reboot the PC start Content Manager and run an Extended Database repair, may or may not take a long time. May not need doing however I have had zero problems with any patch by doing this, never hurts to make sure. When finished reboot PC again and try running Trainz.
If when launching Trainz you get a black Screen or problems with the display, check that the resolution in TrainzOptions.txt is the same as you have it set in the Options on the Launcher Problem. This was a problem supposedly solved with SP3 however it may be retaining the initial wrong default setting from your existing install. Trainz, if using a Flat Screen Monitor should be run at the displays native resolution.
If you are having problems with DirectX you may need to install the DirectX9c runtime files from Microsoft, it will co-exist with DirectX 10 and 11 which are not fully compatible with DirextX9c. Some Win7 systems seem to work OK without using DirectX9c, mine did, however it may be related to the graphics card in use, I installed 9c anyway just to be sure.
I also set the properties for all the Trainz files to run as Administrator, that may well be part of the problem with saving if Trainzutil or TadDaemon are running as a normal user and maybe can't write to Program Files.