Run cmd as admin
Run diskpart
TYPE THE FOLLOWING COMMAND
List disk
Select disk
Clean
Create partition primary
Select partition 1
Active
Format FS=NTFS
Assign
Exit
Insert Windows 7 disk
Change directory to CD/DVD drive
Change directory to boot.
Type bootsect.exe /NT60 E:\. E:\ here must be d drive letter of ur flash drive.
You can now copy d content of ur Windows OS installation disk into ur flash drive and use it to format ur computer system
