Why I can't do partition?

Thanks. I found the partition tool bundled with the OS. Then I followed the help steps:
1. Open Disk Management.
2. Right-click an unallocated region of a basic disk, and then click Create Partition ...
THE PROBLEM occured in the second step. I right clicked any visible places on this panel, but just didn't see the "Create Partition" option. I even saw "Deletion Partition". Help me, please... I am waiting on line. Thanks so much.