Blender crashing when using "Auto weights"

I started a small personal project with a model imported from Sculptris.
I used the rigify addon to add the armature, but when I try to add weight with the “auto weight” functions, it loads for a bit and then crashes.
I also tried using the 6.0 version of blender, where the materials are missing and it doesn’t crash, but I cant add a texture.
Any ideas what the problem can be?

Maybe the polygon count is too high for your hardware. Sculptris objects would be much higher in polygon count than something you’d usually rig

Operating System ?
RAM ?
Blender version
Have you tried with a lower polygon count object
Please supply your Blend file

I also tried using the 6.0 version of blender,
6.0 version ? what is this

but I cant add a texture.
Why

Version 2.6.0, my bad.
Im using Win 7 32 bit , 4gb ram, i5 processor.
Im pretty new to this and Im not sure how to lower the polygon count.
Here’s a link to my blender file: