The default disk management utility in Windows 7 lets one resize (shrink and extend)a partition. Let’s see how to shrink and extend a partition one by one:
Shrink a partition or volume
In Windows 7, it has become very easy to manage the disks. The default disk management utility can easily resize any partition on the hard drive.
To shrink a partition, go to Run -> diskmgmt.msc
This will open the disk management tools. Right click on the partition that you want to shrink and select Shrink Volume. You will need to give how much space you want to shrink in MB. If you want to shrink 1GB, you should enter 1000MB or 1024MB and then press Shrink or Alt + S.
Extend a partition or volume
To extend a partition, go to Run -> diskmgmt.msc
This will open the disk management tools. Right click on the partition that you want to extend and select Extend Volume. Enter the space in MB that you want to increase. Please note that if Extend Volume is disabled or greyed out, this is because extending volume only works on contiguous space. So you may need to create some space around the volume in order to extend it.
These tricks also work on Windows Server 2008.