what OS are you using, if vista or win7 then use built in disk manager, will allow non-destructive partition resizing. or use paragon partition manager. partition magic used to rule but no longer, now its pants.
In this day and age it is crazy to say use an empty disk. I have re-partitioned/re-sized etc my main OS drives dozens of times whilst experimenting with different OS's, without disaster, i just always made a backup of my main OS partitiion first (although never needed the backup)
intel i7 3770k @4.4, ASRock Z77 Extreme 4, 16GB Corsiar Vengance 1600 ram, ATI 5850 BE, Antec 1 Case, Antec 1 550W PSU, emu0404, 120gb agility3 ssd OS, 2x60gbvertex2raid0 Games, 3 TB total sata2 Data. win7 x64.
