I am sorry to hear that have had issues with screen on your computer.
I regret to inform you that there is no way to tell if this is hardware or software issue until you test this problem with another monitor. Does this problem remain after connecting a second monitor?
Does it happen with drivers provided by your motherboard maker?
Did you install generic Intel video drivers?
Try latest version for your operating system here:
When I instaled Windows 7 or Windows 8 in this computer, everything works fine (In Windows 8 after install latest driver on motheboard, screen stops flicker), but in Windows 8.1 screen is flickering. I also try instaled different version of Windows 8.1, different motherboard drivers, procesor drivers, and there was always the same problem. Screen was always flickering. This is problem with Windows 8.1. I have no external graphic, but I have tried with external too, but did not help. I have monitor conected with DVI, but i also tried TV conected with HDMI. Nothing is working. Screen in Windows 8.1 is flickering.
I have tested latest version 3345 with several motherboard supporting Intel HD Graphics 4600 and Windows* 8.1 and I did not get flicker issues.
Please test downloading customized drivers from your motherboard maker here:
Also contact your motherboard maker for additional information about this matter.