Yikes! I'm a first time poster so please forgive me if I make an faux pas!

I suddenly lost my wi-fi connection and can't even connect via the LAN. I can't figure out what is going on. I get a ton of random errors about windows systems not connecting. I tried uninstalling the Dell Quickset application (I have a Dell Inpiron 1720) and now it won't let me reinstall. I can't figure out how to re-connect to the internet. I had installed a yahoo toolbar and google desktop recently so I uninstalled those in case that caused a problem. Still no luck. Any tips?

Thanks for your time