How to Change a Partition Size Without Losing Data

Windows Vista and Windows 7
1. Log on as an administrator. Click 'Start' and select 'Control Panel.'
2. Type 'partition' in the Search box.
3. Click on 'Create and format hard disk partitions.'
4. Right-click on the partition you want to expand. Click on 'Extend Volume...' and an Extend Volume Wizard will open. To shrink a partition, skip to Step 6.
5. Enter the amount you would like to increase the volume by beside 'Select the amount of space in MB:' You will only be able to expand a partition by the amount of physical contiguous space left on the drive. Click 'Next' and allow the wizard to finish the procedure.
6. Right-click on the partition you want to shrink and click 'Shrink Volume...' The Disk Manager will check to see if there is enough space to shrink the volume and will then give you a dialog box where you can indicate how much you want to shrink the partition by. The Disk Manager will then shrink the current partition and create another empty partition after it.
Expanding a Partition in Windows or Windows XP
7. Download, install and start Partition Wizard.
8. Select the drive you want to expand or shrink by clicking on it.
9. Click 'Partition' in the menu bar at the top and click 'Move/Resize.'
10. Increase or decrease the number of megabytes you would like to change the partition by beside the 'Partition Size:' entry. To shrink a partition you must have the available empty space within the partition. To expand a partition you must have physical contiguous space left on the drive to expand the partition into.
11. Click 'OK' and select the 'Apply' button.