Archer wrote:

Got a new Lenovo G50-80 Laptop with Windows 10 pre-installed.

Tried to install Windows 7 Ultimate using a spare hard disk (put in
place of the original one). ...

The install went very well but none of the USB work. ...

I will continue to use Win10 but this USB problem has become an
obsession.

"I will continue to use Win10". That doesn't say the USB ports work
under that OS. Do they? If not, I just looked in that laptop's
hardware maintenance manual at:

https://download.lenovo.com/consumer...series_hmm.pdf

Page 53 talks about removing the common ribbon cable for both USB and
audio connections. Hmm, do you get any audio out of the laptop's
speakers? Try play some audio file and make sure you can hear it okay.
If not, maybe that cable is loose or disconnected. Alas, dismantling
the laptop is not what you want to do with a new laptop since that
probably voids your warranty.