To install Windows 7 on a computer without an operating system

Environment :
Clean install of Windows 7

Installation / Usage :
To do this, you'll need to start, or boot, your computer using the Windows 7 :

1. Installation disc
    1a. Go to the Microsoft Store website and complete your purchase.
    1b. On the Order Receipt webpage, click the Additional Download Options drop-down list, click either Download 32/64bit ISO and then click Download.
   
2. USB flash drive
    2a. Download the Windows 7 USB/DVD Download Tool [LINK]
    2b. Under Installation, follow the instructions to download and install the tool on your PC.

Windows 7 installation steps:

1. Turn on your computer, insert the Windows 7 installation disc or USB flash drive, and then shut down your computer.
2. Restart your computer.
3. Press any key when prompted, and then follow the instructions that appear.
4. On the Install Windows page, enter your language and other preferences, and then click Next.
5. If the Install Windows page doesn't appear, and you're not asked to press any key, you might need to change some system settings.
6. On the Please read the license terms page, if you accept the license terms, click I accept the license terms, and then click Next.
7. On the Which type of installation do you want? page, click Custom.
8. On the Where do you want to install Windows? page, choose the partition that you want to install Windows 7 on, or click Unallocated Space if no partitions are listed, and then click Next.
9. If a dialog box appears saying that Windows might create additional partitions for system files, or that the partition you chose might contain recovery files or other types of files from your computer manufacturer, click OK.
10. Follow the instructions to finish installing Windows 7, which include naming your computer and setting up an initial user account.