The memory, the hard drives the graphics cards and the monitors are all working quite fine. I'm running Windows 7 Ultimate, on a 2500k CPU a GTX 960 and a crappy motherboard that had very poor overclocking options. Ok I've been having serious problems with this build, pretty much since I first set it up years ago. At first the problem was that the Nvidia driver kept failing my screen Would blank and it would recover, the problem got gradually worse until I had to reset the system to view anything, then I started getting blue screens of death and I'd have to reinstall Windows. I messed around with graphics cards and various other things, ultimately I couldn't figure out what the hell was going on it, seemed extremely illogical. The system would work with my old card which made me think uh obviously my current graphics card is the problem. This turned out to be completely incorrect. There was a time when my supposedly faulty card was still in the system, it wasn't booting well there was no image on the monitor at least and I had left my computer off for several days. I tried turning it on again one day and the system booted up completely normally as if there had been absolutely no problem. I obviously still kept having problems though and in the end I applied a Microsoft Fix-It which it changed the timeout period so the an error wasn't being reported or something, I can't really remember what it did actually, but that helped. When cruising the Internet whenever, well most of the time, when adverts started playing on web pages my screen would turn off for a second then turn back on it got gradually worse so that when I was viewing for example the Independent newspaper web page it was turning off multiple times a minute. I have a new installation on a new hard drive and didn't bother applying the Microsoft fix it yet which may have changed things. The current problem is that the computer either completely freezes or it was operating fine and the next time I turn it on my monitor doesnt display anything. The monitor in fact was glitching in and out after I changed the HDMI cable it was connected to and when I change the port it was connected to from the motherboard port to the graphics card port. I disconnected my monitor and connected my projector and immediately I could see Windows starting up, this happened the past two times I had a problem and had to reinstall. Windows would not load up however, it would hang on the logo, using the projector I was able to get into Safe Mode while my monitor would barely display anything. In safe mode I had no audio service running and couldn't do that much. But both times after I reinstalled windows my monitor would start working absolutely perfectly from the start. The last error I got before the second crash which made me reinstall Windows again, was an attempt to execute an illegal instruction, which was a new one for me! So is this more likely a cpu or mobo issue? Thanks.