1. If the computer won't turn on.

Check the power plugs and switches in the back of the computer. Sometimes, computers have power switches in the back in addition to the switch in the front.

2. If the computer won't do just about anything you what you want it to such as get to web sites, show your network H drive, or allow you to log on:

Restart/reboot the computer. This solves at least a million problems.