Ok so I finally built my PC for the first time. However every so often my screen will rapidly flash random colours across the screen. Some times its faster than others, and when its slow pressing Ctrl + alt + del seems to work as it clears it.
However it doesn't always work. I'm connected to a LED TV by HDMI cable.
INTEL Core i5 3570K 3.4Ghz & ASUS P8Z77-V LX - Motherboard & CPU Bundle | eBay
That's the motherboard and CPU. I've updated the drivers. I'm running on an integrated GPU for the moment, my Radeon HD 7870 card will arrive tomorrow so if it still happens I'll be able to exclude it. Otherwise what could it be?