I have MacBook Pro OS X10.4 I have gray screen with a black box where it asked to restart a computer. I tried already everything. I repaired hard drive and it is said that there nothing to repair and then I think I deleted something from a library folder. And now it won't start at all. I can't even start in a safe mode, I can't boot from a CD, I can't boot through the R+P+options+control. Please anybody help me.