RCT2 and WW on disc and RCT1 Deluxe on gog work for my computer, but when I try RCT2 TTP I get the message "Unable to Initialize Graphics System". Here are my specs
Windows 7 Professional 32 bit
Intel core2 duo @3.00 GHz
4GB ram (3 usable)
ATI Radeon HD 4300/4500 series (memory 1785mb)
Latest AMD drivers

I have the same on laptop and the desktop (Vista). I can play only with VirtualBox + WIN XP

Edit:
This hack help: http://www.gog.com/en/forum/rollercoaster_tycoon_deluxe/hack_run_rct2_in_windowed_mode