My standard computer troubleshooting procedure is The Three Rs: "Retry, Reboot, Reinstall". There's quite often a Google step in between the last two, though, because reinstalling is a big operation and if there's a quicker route, you might as well try that before the scorched-earth policy. Still, that's the basics. If you're going to ask me for help, this is what I'll do.
Mokalus of Borg
PS - Or this.
PPS - Some problems never get fixed.