If other computers work on your wireless and you are connected to your wireless router with no errors, it likely is a local setting on your machine. I, myself, would start by calling the shop and asking them. They may have set up a static IP address, put the computer on a domain, etc. while they were restoring it. I’ve also encountered viruses that can linger around even after a fresh restore of the OS that cause similar problems. I believe it was a rootkit if memory serves and those are terrible little devils. In any event, start by calling the shop. Also, you may try hooking it up wired to see if you can pull a webpage that way.