I was trying to make a USB drive bootable using command prompt. Using diskpart utility of windows.
But I've done a silly mistake.
After creating the primary partition, I've assign it without formatting. I think that the USB drive is already formatted with NTFS file system. I didn't think that after creating new primary partition all file system is deleted and the drive comes to the raw storage area.

Due to this the drive is showing 0 bites free and 0 bytes in use.
I've tried to recreate the primary partition and format the drive using command prompt and using diskpart also.
But all those are unsuccessful. It showing error. Please show me the way out...