Installing vista compatable games on Vista 64 bit

Hi, could anyone help me I am trying to install vista compatable games on a 64 bit machine. Theme Hospital being a case in point I am unable to even install the game onto the machine as it advises me that it is not 64 bit compatable, is there a way around this? Have been advsied it can be done through DOS but have no idea on Vista as to where this is and what i would need to type. Can anyone help me? are there any other ways other than DOS to let me fool the machine into letting me install the game without running 2 OS's? pc is quad core 2.66ghz, 4gb ram, 896 Nvidia GJZ260 graphics card.

Many thanks in advance

Cheers for that, its just a bit annoying!!

Does anyone know how you can tell if a game bought (which says on the box supports Vista) will infact work on a 64bit machine?? Only in the case of Theme Hospital which fair enough is an old OLD game, but the copy we bought the other day did say vista compatable.

Just seems a bit daft to say vista compatable then not be 64 bit vista compatable is this just temporary until the vista drivers amalgamate better with the 32 bit drivers or is this a permanent problem.

Any help still with making these old but classic games install would still be very much appreciated!