How to repartition computers hard disk

you can repartition your hard disk by using the Shrink feature in Disk Management. You can shrink an existing partition or volume to create unallocated disk space, from which you can create a new partition or volume.

1.      Open Computer Management. ‌To open this press START_KEY and type Computer Management in search bar or right click on computer icon on desktop and click manage.

2.      In the left pane, under Storage, click Disk Management.

3.      Right-click the volume you want to shrink, and then click Shrink Volume.

4.      Follow the instructions.