Windows Vista comes with Disk Management, which even lets you shrink or expand volumes without destroying data on them. No need to buy expensive third-party utilities! Open the Control Panel, type in
partition and press [Enter]. You will immediately see the link Create and format hard disk partitions under Administrative Tools. Click on it to launch Disk Management. Right-click on a partition and you will see the Shrink as well as Extend options. You should defrag the partition before doing the shrinking or 
expanding to achieve the best results, since the operation is dependant on the amount of contiguous free space available.
