[uh this computer]

Hello,

I bought a new USED laptop and was trying to hook it up to my wireless network. On my PC I ran the network wizard. After running the network wizard I still could not connect to the internet through my new used laptop. My MAC laptop is connected to the internet and working fine. That is what I am using to type now. However, my PC will NOT connect to the internet now. It's the oddest thing. I called my internet provider-charter. They said everything is fine on their side and they think something went wrong with my operating system. I tried restarting the computer, unplugging and replugging everything back in. When I type IPCONFIG in I get a IP address from the router but no default gateway. I also cannot run system restore on the computer. Every time I try to run system restore it says it can't reset to that date. Any help/suggestions would be appreciated. Please if you have a suggestion type it in computer-dumb language as this is not my thing! Thanks