Click Start , type cmd in the search box.
How to Format a Disk in Windows 7: A Complete Step-by-Step Guide (USB, HDD, SSD)
Type exit to close DiskPart.
Type clean — this removes all partitions and data from the disk.
Select the new partition: select partition 1 windows 7 format disk
Your drive will be formatted and ready to use in seconds. Disk Management gives you more control, especially for unallocated space, partition resizing, or formatting drives that don’t appear in “Computer.”
Windows 7 will format the disk and make it visible in “Computer.” For power users or when the graphical options fail, Command Prompt is your friend. Click Start , type cmd in the search box
Assign a drive letter: assign letter=F (choose any available letter)