Disk Management Partition / Shrink

Have you ever needed to partition or shrink your existing disks on windows. No worry windows comes with a couple of inbuilt utilities for this.
1. An UI based utitlity that cen be launched as  

: windows -> run ->diskmgmt.msc

: or windows->computer->right click -> manage

2. Alternatively a command line utility called DISKPART which relatively powerful than the UI disk manager. This can  be launched as windows ->run -> diskpart