Vista won't let me extend drive partition

[Xan]

hi
i am using vista but unable to extend partition on hard drive with it.I have a 20GB partition i am looking to extend it. but as i try to extend form from manage it gives me error message saying: "Diskpart failed to extend the volume. Please make sure the volume is valid for extending."
can some one help me ?
thank you

[timon]

i think it will not allow you to extend or format drive as you are trying on booting drive so may be later version of diskpart can help you. may os problem ..its better if you use any application to extend a partition like partition manager ..

[Lillebror]

you can use Gnome Partition Editor for extend a partition .A disk device can be subdivided into one or more partitions. The GParted application enables you to change the partition organization on a disk device while preserving the contents of the partitions.

With GParted you can accomplish the following tasks:

* Create a partition table on a disk device.
* Enable and disable partition flags such as boot and hidden.
* Perform actions with partitions such as:

• create or delete
• resize or move
• check
• label
• copy and paste

[Calvin K]

You can use the Diskpart.exe utility to manage disks, partitions, and volumes from a command-line interface. You can use Diskpart.exe on both Basic disks and Dynamic disks. If an NTFS volume resides on a hardware RAID 5 container that can add space to the container, you can extend the NTFS Volume with Diskpart.exe while the disk remains a Basic disk.

Use the extend command to incorporate unallocated space into an existing volume while preserving the data.for more information check here http://support.microsoft.com/kb/325590