Sudden appearance of multiple colored horizontal and verical lines?
OK, just woke computer up from "sleep," and everything is working fine. A few minutes later, all of a sudden, the monitor screen is filled with colored vertical and horizontal lines...and nothing is working nor is there anything else on the screen but the lines. Manually, shut down and rebooted. Opened with options on how to continue. I chose Normal Mode. Computer and screen now working as they should for the last hour. Any idea what happened and whether or not this is serious?