connected to internet but can't load any pages any browsers

I can open Firefox, IE, Google. When I open any one of them I get the following error message: Firefox can't find the server at us.data.toolbar.yahoo.com. I am not sure what is happening. Also, when I start my computer I get an error "SPUpdate.exe error occurred". It gives me three options: Continue, restart or close program.

I am using my sons computer to send this because of the problems that I am having on mine, so I can't download ISG for you to get my computer information.