To begin with i would like to share that I've had this computer for about 4 years and i have done different amount of formats and install between xp/windows 7 and windows 8 recently. they've all worked like a charm. I recently tried to install two hard drives into an ide port i had open and it dint work because my computer was lacking power. took them out and ran back my windows 8.1 but since my computer was opened up i decided to turn it off - Powerbutton and close it and when i turned it back on, some system32 file was missing, recovery type mode. well i said no problem il put my DVD and use boot-sect to fix which I've done before too. well so it happens that the dvd's for windows 8.1 loads to the blue windows logo no loading gif just black screen with the blue windows logo and it stays there for ever, same with usb drive. those two sources were tested in a separate computer and it reads it just fine. what can it be? btw my motherboard is msi-n750