You need an iso file for making a bootable USB when you are unlocking computer password,especially with free software.
The iso file can be easily downloaded from Microsoft website.
https://www.microsoft.com/en-gb/software-download/windows7
Or ask for their help
https://www.lifewire.com/how-to-reset-a-windows-7-password-2626297
https://www.recoverywindowspassword.com/