Step:-1 Right Click on This PC / My Computer and Click on Manage
Step:-2 Now Click on Disk Management.
Step:- 3 Right Click on Drive/Partition That you want to Divide and Click Shrink Volume.
Step:- 4 Type in amount of space you want to shrink to and click shrink.
Step:- 5 As seen below the drive is divide in two parts as specified with one partition showing unallocated space.
Step:- 6 We will assign a new drive to this unallocated space. Right Click on unallocated space, Click New Simple Volume.
Step:-7 In next window click on Next
Step:- 8 Now click on Next.
Step:- 9 Click on Next.
Step:- 10 Here click on Next button.
Step:- 11 Click on Finish.
Step:- 12 A new drive is created with specified size.