Bootable USB Key with command in Windows 7

A bootable USB flash drive can be a handy thing to have. For one thing, you can try out other operating systems without messing with your hard drive. For another, you can have a tool for repairing Windows systems that won’t boot. Or you can use it to install software on a PC that has no DVD drive.

Bootable USB Key with command in Windows 7

There are various ways to make a USB key bootable, This approach uses a built-in command-line utility that comes with Windows 7 and 10.

The command is diskpart and it can be used for a number of disk operations as well as for creating a bootable flash drive. It is actually a suite of commands in a separate shell that is described at this link.

This tip is for more experienced computer users and uses a powerful command that can wipe out a disk.

Open a command prompt with administrator rights and enter the following sequence of commands:

diskpart
list disk
select disk {number}
clean
create partition primary
select partition 1
active
format fs=fat32 quick
assign
exit

In the [select disk] command, replace {number} with the drive number of your USB drive as indicated when you ran the list disk command.

Check and double check you choose the correct number since this procedure erases everything on the drive you select.

The format command given above will create a FAT32 file system. This creates a bootable USB key that can be used for many purposes, once appropriate files are added. For example, it can be used to install Windows 7 (if the flash drive is at least 4 GB and you have a Windows 7 license).

Note that If you wish to use the USB key to actually run Windows 7 or otherwise need NTFS formatting, you will need to replace [format fs=fat32 quick] with [format fs=ntfs] and also modify the boot sector.

Software for creating bootable USB keys

If you prefer a graphical user interface to the command line, you can download and install one of the numerous free programs for making a USB key bootable. One program that has a number of functions in addition to making a key bootable is EasyBCD. The procedure for using a bootable key to install Windows 7 is described here and many other places.

A standalone utility that does not require installation is Bootable USB Drive Creator Tool. The download is in the RAR format and you will need a utility like 7-Zip to extract the files. This utility uses DOS boot files.

Check your BIOS

To boot with a USB key, you may have to configure your BIOS. Check the settings for your particular hardware.