If I were you, I wouldn't try to partition the hard disk. Perform a full backup and then move it to the new system. It's that simple.
I had to reinstall a few systems, but moving the hard disk to a new system wasn't the reason. They were used by people who basically installed everything they could find on the Internet which eventually creates a real mess. If you've installed every tool, anti-virus, registry cleaner and game that you could find, then reinstall from fresh.
I don't like partitioning hard disks as it doesn't necessarily help when performing backups. I simply restore the system when something goes wrong; with eSATA and USB 3.0 external drives, it's much faster that reinstalling.