Why Won't My Laptop Let Me Log In?

Hello,
I have a Dell Latitude. First when i start the Computer up it says "An I/O operation initiated by the registry failed unrecoverably. The Registry could not read in, or write out, or flush, one of the files that contain the system's image of the Registry" so i press ok, and it takes me to the log in window. I put in my password in and it says " Windows cannot load the locally stored profile. Possible causes of this error include insufficient security rights or a corrupt local file" then "Application failed to initialize property" and "System cannot log you on because the domain USER-********* is not available"

I have tried Safe Mode and all the other modes, Operating System Recovery disk, and none of it works. PLEASE HELP!!!