How to Fix Windows Unable to Complete the Format 1-Go to Start 2-Right click on My Computer or This PC 3- Click on manage 4- Next, it will open up the Computer Management 5- Click on Disk Management 6- Then the window will show you all the drives on your PC 7- You will see a drive with black color and it is written "unallocated" 8- Right click on the drive that you want to format, and choose New Volume 9- A New Simple Volume Wizard will appear. Click next, 10- Specify the Volume Size. Just click next, 11- Assign Drive Letter or path, just choose any letter and lick next 12- Format partition, and click next 13- Now we're done! Click finish 14- Everything backs to normal! Good as new If you found this useful, don't forget to say Thanks!