On return from holiday my computer wound not boot . Fans were on but no splash screen. I found a couple of similar examples on the forum and as suggested turned everything off unplugged all peripherals, held down power switch for 40secs reconnected everything and tried again this time I got as far as the desktop opening but the system thn hung -I think when loading the grraphics driver. I repeated this all a few more times with same results -no initial boot eventually getting through using the 'discharge' sequence but then hanging when loading startup drivers. My Computer is about 3yrs old. Is there anything I can try to fix or at least narrow down the source of the problem before I buy unnecessary hardware?