Setup was unable to create a new system partition or locate an existing system partition - Can't install Windows server 2008 R2

I am trying  to install Windows server 2008 R2 on DELL PowerEdge R620 server, & facing issue.

"We couldn't create a new partition or locate an existing one.  For more information, see the Setup log files."

Resolution:

1. Set your PC to boot from DVD via BIOS
2. Put the DVD in and let it load until you get to this screen:
3. Once at this screen, press: (SHIFT+F10) to get a CMD window

Step by step instruction:

1. MAKE SURE YOU SELECT THE DRIVE YOUR INSTALLING WINDOWS TO NOT ANOTHER. In the CMD window, type in Each Command and Press <ENTER> Key as follows:
   
   DiskPart <ENTER>
   list disk <ENTER>
   select disk 0 <ENTER>
   clean <ENTER>
   create partition primary align=1024 <ENTER>
   format fs=ntfs <ENTER> (Will Take a While)
   assign <ENTER>
   active <ENTER>
   exit <ENTER>
   exit <ENTER>
2. After it completes, exit the INSTALL COMPLETELY and reboot.
3. Once you are back in, go about installing Windows just DO NOT ALLOW Windows to create a new partition, use the only one there.