windows 7 - Ridiculous DISM errors trying to install drivers

I'm trying to install some USB 3.0 drivers which I think are right for my motherboard (the computer is a Compaq laptop with "15-s108na" on the label on the back and I got the driver at https://driverscollection.com/Search/ by looking up compaq 15-s108na usb 3.0 and picked the first thing, so I think I have the right thing) into the boot.wim and install.wim files of a bootable Windows 7 Ultimate Edition USB key so I can install, because I keep getting errors about CD/DVD drivers being missing.

Now I'm trying to install it by following this guide: http://codeabitwiser.com/2014/03/how-to-install-windows-7-with-only-usb-3-0-ports/ but I'm having so many problems...

What I did by steps in the link

Step 1:

Downloaded the driver .exe shown above and all the drivers shown in the list in the link for good measure (I don't think putting them in the boot.wim will cause any problems if they aren't useful?) except the last one (VIA VL800/801 & 805/806 USB 3.0) because the link just redirects to the home page and I can't find it.

Step 2:

Made a new folder in Documents called >b>mylifeishell.

Made USB3 and mount folders inside that.

Put all the drivers including Compaq .exe in USB3. (I extracted the folder in Intel(R)_USB_3.0_eXtensible_Host_Controller_Driver.zip and put that in but I didn't know what to do with USB3.0_allOS_2.1.28.1_PV so I left that the way it was).

Step 3

Fished the boot.wim and install.wim files out of my bootable Windows 7 Ultimate USB stick and put them into mylifeishell folder, as instructed.

Step 4

Opened cmd.exe as administrator.

Typed dism /mount-wim /wimfile:boot.wim /index:2 /mountdir:mount
Result was:

Error: 2

The system cannot find the file specified.

So insteaad, I got more specific with the location of boot.wim and mount:
dism /mount-wim /wimfile:"C:\Users\name\Documents\mylifeishell\boot.wim" /index:2 /mountdir:"C:\Users\name\Documents\mylifeishell\mount"

This works, a percent bar appears and charges up to 100.0% and says The operation completed successfully.

I then proceed to type the second line, dism /image:mount /add-driver:"usb3" /recurse, provoking this error;

Error: 2

Unable to access the image.

Make sure that the image path and the windows directory for the image exist and you have Read permisions on the folder.

I then modified the command with exact path of the USB3 folder again; dism /image:mount /add-driver:"C:\Users\name\Documents\mylifeishell\USB3" /recurse

This gives exactly the same error, 2, as last time, so I alter the image:mount part too in case it needs to be reminded what directory it's mounting. dism /image:"C:\Users\name\Documents\mylifeishell\mount" /add-driver:"C:\Users\name\Documents\mylifeishell\USB3" /recurse

Resulting in;

Error: 3

Unable to access the image.

Make sure that the image path and the Windows directory for the image exist and ou hve Read permissions on the folder.

Then I tried to specify a specific file in the USB3 folder, without specifying the file path of the mount folder: dism /image:mount /add-driver:"C:\Users\name\Documents\mylifeishell\USB3\USB3.0_allOS_2.1.28.1_PV.exe" /recurse and got Error 2 again.
With mount file path:dism /image:"C:\Users\name\Documents\mylifeishell\mount" /add-driver:"C:\Users\name\Documents\mylifeishell\USB3\USB3.0_allOS_2.1.28.1_PV.exe" /recurse . Got Error 3 again.

I have no idea what to do and am slowly running out of time here. Maybe if someone could make me the .wim files and leave them in a download link. I would happily kiss your dog on the lips and send you Christmas cards forever.