How to resize the primary partition in Windows Server 2008?

We have a Windows Server 2008 with C: and D: drives. I freed up 30 GB from the D: drive using the "shrink volume" option and that needs to be added to C: drive. But the extend volume on the C: drive is disabled.

Can you please tell me how can I add the free space at the end of D: drive to C: drive?

Your D: drive should be in extended partition. After shrinking, the free space is also in extended partition. To extend C: drive, there must be some contiguous unallocated space on the right side of C: drive. Now it's free space but now unallocated space, it's on the right side of D: drive but not C: drive. The two reasons cause extend volume greyed out. You need to backup D: drive -> delete D: drive -> delete extended partition -> right click C: drive and select "Extend Volume".

http://www.partition-magic.org/windows-server-2008/windows-server-2008-resize-partition.html

I think you can't do it while the OS is started. That's why I can tell you to try to resize it with a linux live-cd, like Gparted-LiveCD, wich support many types of partitions. keep thinking to backup your datas before resizing.

To extend a partition, there should be Unallocated space behind it. By shrinking a data partition, the unallocated space is behind this data partition, so you cannot extend system partition by Extend feature, for details, see how to shrink and extend partition under disk management http://www.partition-magic-server.com/resource/shrink-extend-server-2008.html

You can only extend a partition if the free space is just after. So after extend, it's a continous partition. You can't have C partition using space after the D partition

Another option may be to temporarily move the data on the D: drive (if possible) elsewhere, blow away the D: partition, extend the C:, then re-create the D: and move the data back.