Before you call tech support, I would highly recommend that you do the following, as it will make the entire experience smoother:
Start by restarting your computer. This step alone will fix 99% of your issues.
If it is an issue with your internet connection, restart your router and modem (the box[es] with the blinky lights).
If you are connecting over WiFi, please ensure that you are connected to the WiFi network itself. Then check to ensure that the cable connecting the router and modem is plugged in to both devices (they have a tendency to slip out of the connector isn’t very tight).
If you are connecting over a cable (Ethernet), check to ensure that the cable is tightly plugged in. They have a tendency to slip out.
If you are running Windows, hold the Windows key and R at the same time. Type (don’t type the quotes) “cmd” into the box and press enter. Then type in (don’t type the quotes) “ipconfig /flushdns”.
Keyboard, Mouse, Etc.———-
If it is an issue with your mouse, keyboard, or any other peripheral, check the cable. If the cable is completely plugged in, try another plug (ex. another USB port).
If it is a program (ex. Microsoft Word, Internet Explorer, Google Chrome, etc.) related issue, start by running a antivirus and antimalware scan. I’d suggest Microsoft Security Essentials (Called Windows Defender on Windows 8 and higher) and Malware-Bytes AntiMalware. Even if you allready have an antivirus, I’d highly suggest you still run a scan with MalwareBytes.
What was the last thing you did? Did you install a program right before it stopped working? Did you hit a button somewhere, then it stopped working? Retracing your steps and backtracing changes to your computer can often solve your issue as well.
If it isn’t starting—————-
Check to ensure it is plugged in. Then, check to ensure that the screen is plugged in and on.