I downloaded Windows 10 for free because somebody told me it was so "modern" and "cool".
Far better than Windows 7.
I was fooled!
Can you wipe it out and install 7?
I asked my technician and he said it could be possible but expensive

Maybe I should ask another one
Yep. Find another techie. If you have the install disk you could always buy a new hard drive, solid state if you want some serious speed. Unplug what you have now and install 7 on the new drive. There's no risk and it would be a lot cheaper to do.
Thanks for your advice Iceweasel
There are even less expensive ways than that. Keep Win 10, download and install Classic Shell to replace Win 10's Start Menu, download an app that will uninstall most of Win 10's bloatware, download and install firewall blocks to stop Microsoft's telemetry (spying), disable Edge and Cortana, yes disabling Cortana is possible.
For the most part my Win 10 looks and feels like Win 7.
Oh and you can also download and install the old Windows games but not from the Windows store.