The computer in my sig: i5 2500k @ 4.3 GHz w/ hyper 212+ GA-Z68-UD3H-B3 MSI 280x 3GB Corsair Vengeance LP 2x8GB I have been running this very stable for many years. Recently I put a fresh install of win10 on and today it locked up three times. The first time while playing 'Ni no Kuni II Revenant Kingdom'. The computer felt very warm so I opened it up and it had a think layer of dust behind the fan on my heatsink. Pulled it off and gave it a proper cleaning. Last night I was playing NieR - Automata and it ran smoothly. It was not running Ni no Kuni very smoothly today, it felt a bit laggy. When it locked up I had to hold the power button and it took many tries to get it to boot into windows. I played A Hat in Time for a little while and it locked up again with white horizontal lines on the screen. It took many tries to get it to boot into windows. I reinstalled the AMD drivers. Boot repair didn't find fix anything, sfc/scannow and DISM /Online /Cleanup-Image /RestoreHealth I've also run windows defender, Malwarebytes and spy bot. I think my previous overclock was at 4.2. this was reverted by the bios. 4.0 failed, 3.8 held but again it locked with a white screen while watching a video in youtube. Any ideas on how to identify the problem? Could it be software or most likely hardware? I not planning on building a new computer until I finished my PhD and had started working (6 months to a year). My wife has just replaced her MacBook air (mid-2013) so funds are kind of tight as we are both finishing our PhDs and have a two-year-old. How much I'm I looking at to get a decent CPU/MB/Memory that will be a least a bit of an upgrade on here, £300?