Ok guys, so my monitor was faulty and I bought another one, when I set up my pc with the monitor there was no display, no beep but everything was running except there was no red blinking light under the power light. Anyway, so I opened it up and saw that the power cable to the hard drive came out somehow and when I plugged it back the pc started up and I logged in and all but apparently the pc wouldn't recognise my router, after a couple minutes it get the blue screen of death saying "bad pool header" and when I restart it sometimes the display goes blank, I have tried taking out the CMOS, disassembling and reassembling but still nothing, guys please help as I am in complete stress and this is my first "good" pc I have invested my whole savings in.