Vista on a partition to Vista on separate drive

I have a Mac Pro with one 750Gb drive partitioned 50:50 MacOS and Windows Vista. Vista is getting slower and slower as it fills up the 350Gb allocated. I have an unused hard drive in the Pro. Is there an easy way to transfer all the Vista 'stuff' including files and programs from the partition to the empty hard drive or do I have to go through the tedious process of backup-delete partition-format unused drive- install Vista, every single Windows program and all the files again?

Thanks for your help

Distraught - Surprised no one know how to do this.