GeekyHeart

In the past, in order to re-size your partition without deleting it, you had to use third-party software to accomplish this task. Most notably was Partition Magic which still works well. Now, Bundled with Windows Vista , the functionality to re-size your partitions is right in Disk Management.

Here are the instructions and screens to re-size your partitions:

1. Click Start
2. Mouse Over Computer – Do not click it!
3. Right-Click Computer
4. Select Manage
   
5. Click Disk Management under Storage. You may need to expand Storage if it is not expanded.
   
6. Now you see all of your disks. In my screenshot above you can see Disk 0, Disk 1 and Disk 2.  Disk 1/2 is an external card reader. Disk 0 is my internal HD on my laptop (my primary HD).  I now have the option to “Extend” or “Shrink” a volume. Extend means to expand it (make it larger) and shrink means to make it smaller. You can see that my Disk 0 has 4 partitions and one block unallocated space (for 3.22GB).
7. Right-Click on the partition you want to Extend or Shrink
   
8. Select Extend Volume OR Shrink Volume depending on what you want to do
9. Follow the instructions on the screen.