ive been trying to play classic games such as leisure suit larry blade runner and monkey island  on my new pc which needs 64 bit  but the problem is they wont install  all coming up with messages saying things  along the lines of you're operating system is not compatible ask you're software publisher  for a 64 bit version. is there a way to fix this and allow my comp to run it or trick it to doing so any help will be grately appreciated

I'm going to assume these older games are not compatible with Vista 64-bit, so therefore, you cannot play them.

You could try http://www.dosbox.com/ on some of the really older games

Yea, some of those sound like they need DOS, and DOSBox should fix the problem.

Use a program called ScummVM. It allows you to play any of those old school games by creating a virtual machine sort of like a Java virtual machine. I use Vista64 and had no issues playing Full Throttle, The Dig, Space Quest, etc.

Yes, ScummVM for the win. It also lets you apply filters to the graphics to smooth out the pixellation a bit.