That said, Moonfroh is absolutely correct that the first thing you should do, should you ever run in to any problem with any program whatsoever, be it a video game or a desktop application, is try restarting the app in question, and then rebooting your computer. I'd leave power cycling the modem until the last because unless you outright have no Internet connection that probably will not help.
Around 50% of program woes are solved by a reboot, my old office determined.
Chaos reigns within
Reflect, repent, and reboot
Order shall return.
I used to work IT for a university, and used to get the class to laugh when I would walk in and fix the problem in one minute that the professor was trying to work on for the last 30 minutes. I did it most of the time by walking in, unplugging the device, and plugging it back in.