Need help bluescreen of death,disk read errors,missing kernal and more

My computer was working fine then I installed a new videocard and it worked fine for a week then I had to hard reboot becuase the overclocking program would freeze my computer when I would activate it. Now I get blue screens of death, my hard drive does disk read errors and it randomly tells me that the kernal is missing or corrupt. When the computer lets me get into the OS I cant run games and It will freeze every 3 minutes. Do you think my hard drives are bad? I am useing the Seagate 500gig duel hard drives and they have always made loud noises when I load a program and it would randomly happen too. Currently my cd rom drive doesnt work also so wiping the hard drive or buying a new one and putting windows on it is out of the option. If anyone can tell me whats happening to my computer can you please let me know. I have an i7 with 8gigs of ram and I know for a fact it shouldnt be doing this to me.