ntldr is missing

Hi my friends how are you
last day when i turned my computer on a message were appearing and says "NTLDR is missing" i search for the reason on the web and download the NTLDR fix for usb . i did the whole instructions but when i tried the USB a message were appearing and says "WINDOWS HAS DISABLED DIRECT DISK ACCESS TO PROTECT YOUR LONGFILE NAMES...TO OVERRIDE THIS PROTECTION SEE THE LOCK /? COMMAND" what that is mean ???

please HELP me to fix this problem

THANK You ALL ...