Johncee2000,
*****Disclaimer*****
HP doesn't recommend the installation of Windows 7 on a computer shipped with Windows 8, nor will it support the installation of Windows 7. HP will not provide Windows 7 drivers and suitable drivers may not be available for the hardware in the computer. Also, Windows 7 may not support some of the hardware or software features designed for the computer.
Make sure you create your HP Recovery Discs or USB Flash Recovery media before modifying or changing ANYTHING.
You will need to DISABLE "Secure Boot" and maybe ENABLE "Legacy Support" in the "BIOS Secure Boot cofiguration" on the settings page shown below before you can attempt to install Windows 7;
Additionally, as the hard drive is partitioned as GPT, you must boot the computer using the "UEFI - CD/DVD drive" in the "F9" boot menu. If "UEFI - CD/DVD drive" or something to that effect doesn't exist in the boot menu, please post a screen shot and/or descibe the listed boot options.
I suggest using a Windows 7 SP1 disc for the best intallation experience. If you need a Windows SP1, please see "How to Install Windows 7 Without the Disc" to download and create your own. If the DVD refuses to boot as UEFI, you may need to use a USB Flash drive (may require DISABLING "Fast Boot" in the BIOS) as the installation media. Please download the Windows 7 USB/DVD download tool to create a Windows 7 SP1 USB Flash drive.
Here are the specs for your HP Pavilion 23-b012 All-in-One Desktop Computer and its AABRZ-AB (Azara) motherboard. The Windows 7 drivers from the HP Pavilion 20-b014l All-in-One Desktop PC Drivers & Downloads page should work for your computer.
Please post the Windows Device Manager's "Hardware Ids", as shown below, if you have issues installing the proper drivers;
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