Thats so much to go one.
Note: when asking for help you are REQUIRED to provide as much information as possible. Computer specifications, recently added software and or hardware, recent power outages/surges, Programs running, running processes, anti virus installed, anti spyware installed, when did the problem start, what have you already tried, internet connection type, computers connected to network, router brand and model, Modem brand and model, is windows uptodate, error information in event viewer.
You get the point, I hope. The more information the Better.