Question

I’m use reg->SaveKey(“Software”, “D:\1.reg”). But getting empty file, without data.

void __fastcall TForm1::Button2Click(TObject *Sender)
{
      TRegistry *reg=new TRegistry(KEY_READ);
      reg->RootKey=HKEY_LOCAL_MACHINE;
      reg->OpenKey("Software",0);;
      reg->SaveKey("Software","D:\\1.reg");
      delete reg;

}

Answer 1

SaveKey is a loose wrapper around RegSaveKey(), the documentation of which states:

The calling process must have the SE_BACKUP_NAME privilege enabled. For more information, see Running with Special Privileges.

User tokens do not normally have the SE_BACKUP_NAME privilege enabled. In order to meet this requirement you need to:

1. Run as administrator.
2. Add the SE_BACKUP_NAME privilege to your user token.

The other requirement you must adhere to is that the output file must not exist before you call SaveKey.

See this EDN article for C++ code illustrating the method.