Hi:
There are no W7 drivers for the motherboard in that model from HP.
Looking at the product specs, you can probably use the following drivers, but I cannot guarantee 100% that this will work perfectly, though I am pretty sure they will...
If you hate (or have software that doesn't work on) W8.1 that much, and want to roll the dice, then here is what you need to do to install Windows 7, 64 bit...
First, make your set of W8 recovery media in case the experiment is not successful or you decide you want to reinstall W8.1 in the future.
Then you have to change 2 BIOS settings in order to install and run Windows 7.
After you have installed W7, below are the links to the drivers I believe will work.
First, install the AMD chipset driver and reboot. You want the 49.7 MB chipset driver file download.
http://support.amd.com/en-us/download/chipset?os=Windows 7 - 64
Next, install the AMD grphics driver and reboot.
http://support.amd.com/en-us/download/desktop?os=Windows 7 - 64
Next, install the audio driver and reboot. Accept the agreement, download and install the second driver on the list.
Ethernet: Download and install the 5th driver on the list.
Wireless: I believe this driver will work for the wireless card your PC has.
If the chipset driver doesn't install the USB drivers like it is supposed to, then download and install both of these drivers.