The HP Envy h8-1534 is a Windows 7 desktop PC. It includes a built-in HP Multi-Display Capable technology that supports two monitors at once so users can multi-task. The HP Envy h8-1534 was released in January 2013.
This happened to me once. What I did was unplug the pc, remove the clock battery, hold power button (while still unplugged) for 10 seconds, pop the cmos battery back in and turn it on. It also may be a power supply issue