I've been encountering the frustrating "Input not supported" error while launching RCT3 on Windows 7 ever since I switched to a new monitor.
This is because RCT3 relies on a persisted resolution info stored in an Options.txt file when the current resolution setting on this file is not supported by your monitor, it would result in "Input not supported" error.
I found the following fix that "works" (for Windows 7)
> Start > Run
> Type "appData"
> Search for the following folders: "Atari/RCT3/" and look for Options.txt
> Edit Options.txt in Notepad
> Change the resolution to match your current/supported resolution of your monitor
> Save and close the file.
> Launch RCT3 and now it should run!
This is because RCT3 relies on a persisted resolution info stored in an Options.txt file when the current resolution setting on this file is not supported by your monitor, it would result in "Input not supported" error.
I found the following fix that "works" (for Windows 7)
> Start > Run
> Type "appData"
> Search for the following folders: "Atari/RCT3/" and look for Options.txt
> Edit Options.txt in Notepad
> Change the resolution to match your current/supported resolution of your monitor
> Save and close the file.
> Launch RCT3 and now it should run!