If you have a Windows 7 license for multiple computers, and you want to install it on many computers, then a great way is to install Windows 7 from USB drive.
You can use WinToFlash to create a bootable Windows 7 installer USB drive from a Windows 7 installation DVD or CD(s).
How To Create a Bootable USB Installer For Windows 7
• First make sure that you have a USB drive with at least 3 GB capacity. The process will erase all the data in the USB drive, so make sure you have the backup of all your data on USB.
• Put the Windows 7 installer DVD in your drive and plug in your USB drive. Download WinToFlash. Unzip the folder to your desktop and run the WinToFlash.exe file.
Note that when running WinToFlash for the first time, you may see the WinToFlash DLP_NotFound error message. You can safely ignore this error message.
• On the main screen, click on the Window Setup Transfer Wizard. This will bring you to the wizard mode where it automates (almost) the whole process for you.
• On the next screen, there is an option for you to go into the Advanced mode and tweak some of the settings. You can ignore that (if you are not into tweaking) and click Next to proceed.
• Point the Windows file path to the Windows Installer DVD directory. Point the USB drive to the USB directory.
• Click Next. Accept the agreement.
Once you see the following message, the whole process is done. You can now boot Windows 7 from your USB drive.
That’s it. Now you have a bootable USB installer for Windows 7.