computer wont connect to internet

I saw a free screensaver and started to download it. It ended not being something I wanted. Went to uninstall and during this process my computer froze. I had to manually shut it down. Now I can’t connect to the internet. I tried to restore my conputer from earlier date and that didn’t help. I ran my spyware and did disk clean-up and that didn’t work. I have talked to my internet support and each person I talk to tells me to do something different. Says my firewall is blocking the connection, change from usb cable to ethernet cable (blue to yellow cable) that didn’t help. Can it be fixed?