BCDEdit.exe, Boot Configuration Data or BCD Editor tool in Windows helps you manage boot configuration parameters. See what you can do if it has stopped working.

This issue typically arises from a missing BCD entry or an incompatible hard drive driver. Windows Boot Configuration Data does not contain valid OS Entry ...

Information about the startup environment on a machine that uses the Vista Boot Manager is included in the Boot Configuration Data (BCD) store. Information about bootable operating systems is ...

In the Boot Configuration Data (BCD) of the imported image, set RamDiskTFTPBlockSize to 1456. In the BCD of the imported image, set RamDiskTFTPWindowSize to 4.