it seems so, i booted it up this morning and same problems arose, but this time I didn't have my Nvidia Geforce card connected, I just used the intergrated graphics. Also, I took out all the USB cables and hard drives to see if I still get the error, and I still do. When using just one hard drive with Windows, there aren't as many BSOD's, more a blank screen and a problem with the graphics as the monitor goes back into standby. When loading Windows startup repair, it booted in, but middle way gave an unable to use memory error, 2nd time, I just failed with a 'send or don't send' windows error, and third time in a row, the PC just shut down. I know 400w is probably not the best PSU to use, but my old one seems to be working fine in another PC. I thought maybe this would've ruled out a faulty motherboard but that doesn't seem confirmed.