Windows 7 and BIOS not recognize USB (2 problems)

I have an Acer Aspire F 17 F5-771G-510R

Problem 1:

I installed a copy of Windows 7 (CD purchased from eBay).

Installed successfully. But it would not connect to the internet.

I found a video on youtube explaining how I could use a USB wifi stick to go online, find and download the network adapter drivers needed.

I happen to have a USB wifi stick, so I tried to install it but nothing happened.

This is when I realised that the USB ports were not picking up USB sticks. I tried all ports and used a few different sticks. Nothing.

Back to youtube to get a fix for this problem but all the videos for "USB stick not being recognised" tell me to go into Disk Management where (in their videos) you could actually see the USB stick in some form or another.

But when I go into Disk Management (when a USB stick is plugged in) there is nothing there, nothing at all! So I'm at a loss. I'm wondering though, if this is related to a second problem...

Problem 2:

So, I'd had enough and decided to get another copy of Windows 7 from eBay and install that instead.

I purchased another Windows 7 OS on ebay. This time I received a download link. I downloaded it, copied it to a USB stick, then set Boot to USB in BIOS.

Plugged the USB in and restarted the computer, expecting it to start installing Windows 7 from the USB stick. Instead, a black screen came up with one line saying that the device is not bootable.

Is this second problem related to the first? Or is it a separate issue? I was trying to boot from the USB stick because I had presumed that it was Windows 7 that had the issue with USB ports (not BIOS).

All I can think is, either some additional configuration is needed on the USB stick before trying to install an OS from in on boot; or... both Windows 7 and BIOS cannot recognise USB's for some reason.

I previously had Windows 10 installed on this machine and had no issues getting online or with USB's being picked up. But I find Windows 10 very slow and have had enough of the constant forced updates shutting me down when I'm in the middle of stuff.

I really want to get this machine working properly with Windows 7. Please help.