No Keyboard Or Mouse when downgrade to windows 7 please help

Im having issues with windows 7, I am having difficulties installing it on some new machines, the computers im trying to install it on are an Acer xc 704
I got it from office works it came with windows 10 on it however i need windows 7 pro for it to work with our servers and mainly some of the programs we use in our office.

The issue started as soon as we put the installation disk in, I had to change security setting in bios to allow it to boot from disc, when I finally got to the install menu, I lost function to keyboard and mouse even though they work fine in the bios, did some googling and found this was a common issue due to new computer having usb 3 ports and windows 7 not containing drivers, however the keyboard and mouse was plugged into usb 2.

I then tried to run a bootable usb of another verison of 7 (not the version we needed but was an experiment to see if I can get it installed) After changing uefi settings to legacy I was able to then boot from usb.
I progressed abit further this time I could then progress through the installation menu, once I got the the partition section I had more issues the hd needs to be in mbr mode or something and could only be converted through a third party program, luckily I found a way to do it through cmd, I also got past this hurtle, I successfully managed to install windows 7 (not the right version but it was technically installed)
When the computer restarted to complete installation, I was brought to the first use menu the next step was to enter a username and password and sure enough keyboard stopped working even though it was in usb2 port.

I then went looking into getting the correct drivers onto the install file through mounting the boot and install wim in cmd, I was able to load some usb 3 drivers into the correct version of windows I wanted to load, I got this version on to a bootable usb and went for a new attempt, same results as last time (I could not use the correct acer driver as they are for windows 8.1 and above)

I then though I would install windows 8.1 and try to load 7 through windows, I tried this and successfully installed 8.1,
From here I put the usb in with the desired version of 7 and went at it for the millionth time, I actually managed to install it but then of course keyboard was lost at username page.

At this point I had windows 8.1 and 7 installed on the same machine but could only use 8.1 due to the mentioned issue, I felt I had exhausted all options,
In my desperation i even tried to run the installed windows 7 through some virtual machine software I had on windows 8 in an attempt to complete the installation, however the software I had didn’t have the option to run an existing installation, it wanted a fresh install.

I also tried safe mode. There is no ps2 ports on this machine.

Any ideas? Please help my boss is going to kill me lol