My game constantly crashes within minutes of playing.

No, as in official game update.

As far as Im aware I have the latest one.

Right well a new game is working fine at the moment

With a new game ?

Turn of the memories then. It's a memory hog and if you're game gets really big, it can start not working well.

How do I do that?

It's a new feature in Patch 1.42. 

You can disable the memories in the options completely now.

http://sims3.crinrict.com/en/2012/10/patch-1-42.html

Thanks, if I have anymore problems I'll come back to this post.

It crashed again randomly just now. I was in the process of moving my family to a new home :/

Don't have any other suggestions atm.

Try the tech section in the official Sims 3 forum. Maybe someone else has a bright idea.