To begin with i am sorry but i dont know where to post this but please if anyone can help suggest me a solution.All right here is the problem: went to bios settings and i didnt change anything but before exiting i pressed change to optimal defaults and after that my computer starts, the monitor shows the starting black picture with a dash on top left corner but it does not blinking.After that it shows a message which says something about that the system only works with hard drive and the rest i cant read them cause it is only shown for a second.Then it says launch windows repair system or start windows normally(i've tried windows repair but nothing happened,it said to contact with experts) so when i press start windows normally, windows are starting with these four different colored balls going to the center in order to form the windows logo but before they form it, a blue screen of death comes up for one second and the computer restarts.I know i ask alot but i really need your help!+ i cant change my device boot priority and when im in bios in the boot tab the first booting device is the cd/dvd-rom and then the hard drive but it wont change