Are you encountering Macbook prohibitory sign at startup? do not worry!! because here you will get the appropriate solution on the same. There are some start up warnings alert which may occur with Macbook while booting that represents something wrong has happened in the system. In some scenarios there is Macbook prohibitory sign at startup appears. Usually before appearing this sign you would see gray apple logo. This means that system cannot boot even recognizing the OS due to some issues. As a result you completely lose access of your system and that's why it is extremely necessary to fix the Macbook prohibitory sign at startup. In this type of situation you can diagnose your hard drive problem through disk utility. Besides you can run fsck in single user mode. But if the problem still remains then reinstalling of OS X is the only option. However doing so in order to resolve Macbook prohibitory sign at startup might results data loss. The condition become more troublesome if do not have the proper backup of file. Under such critical condition Mac Data Recovery Software is the recommended tool for restoring the missing file. It is an ultimate solution for lost data recovery.