Wow, well, have been doing more research and the causes and solutions seem to vary widley.
The most common solution people are saying the PSU. Get a better quality one or take the one you have appart and clean it.
Others say disable smooth scrolling in IE fixes it, one person said they disables CE1 (or something) on the
CPU in Bios fixed it... Don't know waht to do... Think the warenty is still good ar Aldi so might just back it up and throw it at them to fix it.
Someone also said they installed the proper MoBo drivers which have power saving options on it and that fixed his. Most of the solutions seem to point at power options and the PSU.