****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 can't clone an installation of Windows 7 made on another computer and expect it to work. You will need to boot the computer from your Windows 7 installation media to install WIndows 7 on your computer. You may need to purchase a new copy of Windows 7 with a Microsoft COA and valid product key.
You will need to DISABLE "Secure Boot" and ENABLE "Legacy Support" in the "BIOS Secure Boot configuration" page on the settings page shown below, before you can attempt to install Windows 7;
or
Additionally, as the hard drive may be partitioned as GPT, you may have to boot the computer using the "UEFI - CD/DVD drive" or "UEFI - USB Flash drive" options in the "F9" boot menu. If "UEFI - CD/DVD drive", "UEFI - USB Flash 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 Windows 7 SP1 for the best intallation experience. If you need Windows SP1, please see "How to Install Windows 7 Without the Disc" to download and create your own Windows 7 SP1 disc. If the DVD refuses to boot as UEFI, you may need to use a USB Flash drive (may require DISABLING "Fast Boot" and/or setting "USB 3.0" to "AUTO" 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. Please note that some computers may not recognize a valid UEFI enabled USB Flash drive if it is formated as NTFS and may require a FAT32 formatted USB Flash drive. You should be able to make a FAT32 formatted Windows 7 installation USB Flash drive using Rufus, UNetbootin, Universal USB Installer, or WiNToBootic. I like Rufus, as it has options for "GPT partition scheme for UEFI computer" and "FAT32".
Most of the Windows 7 drivers on the HP ENVY 17t-j100 Quad Edition CTO Notebook PC Drivers page should work on your computer. DO NOT use any firmware or BIOS downloads from this page. If you still have missing or unknown devices after installing the drivers, please post the Windows Device Manager's "Hardware Ids" for those devices as shown in the example below;
If you have any further questions, please don't hesitate to ask.
Please click the White KUDOS "Thumbs Up" to show your appreciation