I've just come across something in Vista that I think is very strange....Vista (the installation DVD anyway) has no low level disk tools. I found this out after taking a 750Gb drive out of an external case that had been formatted on my Mac Pro and putting it into a new self-build PC that we were setting up. Vista saw the disk and the partitions on it but couldn't install as it was a GPT disk. Ok, so how do you make it a non-GPT disk then?

You have to take it back out of the PC, put it back in it's external case and re-partition it using Disk Utility on the mac!!!!!!

Microsoft..you gotta love 'em!