Do u want to change the partition of hard drives without formatting???

Here is the way,
1)Right click the my computer and select manage>>computer management >>storage >>Disk Management
2)Right click any of the drive and select shrink volume to make the some of the space of the selected drive to be unallocated or select Extend volume to extend the size of the selected drive if there is already unallocated space
3)you can now allocate the unallocated space to a new drive by right clicking it , selecting New simple volume and followed by assigning the drive letter