MySqlInstanceConfig.exe refers to a non-existent mysqld-nt.exe

HI everybody. I am trying to make a batch file .bat to configure MySql 5.1.54 in Windwos 7.
This is the command:

c:\mysql>MySQLInstanceConfig.exe -i -q "-lC:\mysql\install_log.txt" "-nMySQL Server 5.1" "-pC:\mysql\Install" -v5.1 "-tC:\mysql\install\my-small.ini" "-cC:\mysql\mytest.ini" ServerType=DEVELOPMENT DatabaseType=MIXED ConnectionUsage=DSS Port=3306 ServiceName=MYSQLCust RootPassword=fernando AddBinToPath=yes

But, the service doesn´t star because the command file (when seen in the service properties in the service administration window of Windows 7) is the following:
"C:\mysql\Install\bin\mysqld-nt" --defaults-file="C:\mysql\mytest.ini" MYSQLCust
The log file shows exactly the same:

Parameters: "C:\mysql\Install\bin\mysqld-nt" --defaults-file="C:\mysql\mytest.ini" MYSQLCust
Cannot create Windows service for MYSQLCust. Error: 0

But, the mysqld-nt.exe is not in the bin folder of MySql 5.1.54 because it was removed since 5.1. So, it obviously won´t run, because the file to be referenced to is mysqld.exe instead of mysqld-nt.exe.
How can I make the MySqlInstallConfig.exe references to mysqld.exe and not mysqld-nt.exe when creating the service? I think it is a bug, because the very developers removed the mysqld-nt program.
Thanks in advance.

You likely have two version of MySQL on your machine and the MYSQLINSTANCECONFG.EXE that gets called is on the older version. Had the same issue and corrected my Batch file to specifically use "C:/Program Files/MySQL/MySql Server 5.5\MySQLInstanceConfig.exe". This cured the problem.

Thanks for your reply.
No, I use the new, the lattest version, of MysqlInstanceConfig.exe. I make sure of that.
Regards.