This guide does not show you how to setup a dedicated server.
If you have not done this, there are several guides and how-to for it.
It's Highly Recommended that you use editors like Notepad++ or alike. old Notepad isn't good for editing files.
Once you are done with the steps above, make sure the Arma2 server is running before starting up Bec in one of the following 3 ways;
1 - Open Cmd, change the directory to where Bec.exe is located. Start Bec by typing this. Bec.exe -f MyConfig.cfg
2 - Make a shortcut to Bec.exe, then on target do something like. Target| "c:\ServerTools\Bec\Bec.exe" -f MyConfig.cfg
3 - Make Bec run as a service. Don't forget to include the -f argument. you can use windows service to do this, or tools like Firedaemon.
It is Recommended that you start up Bec on Command line the first time to verify that the Config file is working.
Start-up Method nr 1 would also show clues, as to where the issue is, if it fails to start-up on strange exists.