How to resize a disk partition
There are some simple ways to manage your disk partitions to either expand or reduce them. You can choose to download a software that will reduce the hassles towards this issue or try it yourself.
For Windows Vista users
Windows Vista users have the advantage of having a built-in functionality in the “Disk Management” option that will able them to reduce or extend their partitions. If you have Windows Vista, follow the steps below:
Solution 1: Using Disk Management
Step 1: Click on the “Start” menu and browse for your “Computer” icon
Step 2: Use your mouse to right-click on the icon and choose “Manage” from the displayed list
Step 3: Choose “Continue” if the UAC pops up.
Step 4: Select the “Storage” category in the left pane and open “Disk Management”
Step 5: A window will list your disk partitions and to alter them, use your mouse to right-click on the partition that you have to change.
Step 6: From the drop down list, select either to “Extend” or “Shrink: the volume of the chosen partition
Solution 2: Using Command Prompt
Before you start using this option, you should back-up all your important files.
Step 1: Open your Start Menu and enter “diskpart.exe”
Step 2: When a command-prompt window is displayed, type in “list disk” to show the list of all your hard disks.
Step 3: To choose the disk that you want to alter, enter the command “select disk<the disk number>”
Software Download
You can also choose to download a software that will ease the task
Link:
http://www.sharewareconnection.com/titles/resize-partition.htm