First I replaced my h81 mb to a Z97 deluxe to be able to OC my i7 4790 After I replaced and everything went smoothly I have noticed to an issue , when I start my machine it says that "operating system wasn't found".After it I thought it's because I swtiched mb and I didn't really care to format cause I didn't have a lot of thing on my PC.After it I have noticed to another issue , my PC recognizes one of my two hdds but doesn't let me use it so , I created a new partition and it worked , now I restarted my PC and it says again that "operating system wasn't found" please help me what to do, I tried to unplug one of the drives to start from my second drive but it keeps saying that