My machine has a 300 GB hard drive. I'm planning to reinstall Windows 7 on this machine soon. It has three partitions: a System partition, and two equal data partitions for particular types of data (music, photos, docs, etc). These data partitions are too small for the data they hold, and the system partition is large enough to be shrunk.

I want to create four partitions in preparation for the fresh reinstall, a System partition, and three data partitions of varying sizes (40, 50, & 60 GB respectively).

My question: Can I shrink the System volume, create another partition, and make the existing two data partitions bigger without losing any data that is currently on the hard drive?

Or is it better to format the whole thing, and create partitions after (thus removing the current OS) with a partitioning tool booting from CD? Can I reformat and create partitions with the Windows 7 set up DVD?