Connected no internet can't browse

Hello,

I just got a computer from 4 years ago fixed up. OS Windows 7. Lenovo. I've been trying to figure this out all week. I spent enough getting it fixed up and really don't have the sanity or money for more tech work. Anyway, all of my other devices work. On that laptop, it says I'm connected but my browsers won't load/no internet connection. I've tried every CMD prompt there is. config/reconfig/flush/reset/renew blah etc.. I go to my settings and the update and rollback drivers are greyed out. I also get an error that says "DNS server may be unavailable.". I even hooked the ethernet cable directly up to it and still nothing. Someone suggested that I change the channel on my router, but I think it's more than that. Is there anything else I can do or is it looking like another trip to the repair shop again? Oh, btw. Speaking of which. It actually did manage to connect there which is even more confusing.