How to Disable NetBios TCP/IP for Mac

the command you're referencing, is likely applicable before SMBX.

disabling the com.apple.netbiosd Launch Daemon will disable NetBIOS. You should be able to interactively see very quickly in Finder as any NetBIOS-based devices disappear in the Shared Sidebar in Finder.

launchctl unload -w /System/Library/LaunchDaemons/com.apple.netbiosd.plist

Do i just type this in terminal? Because it says "Could not find specified service..."
I'm also running Yosemite.

Yes type it in Terminal. You may need to run that with sudo as such:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.netbiosd.plist

Still says could not find specified service ?

If I disable File sharing that would accomplish what I'm trying here right?

/bin/launchctl load -F /System/Library/LaunchDaemons/com.apple.AppleFileServer.plist;;

I've been able to replicate the error you're getting, when running the command as Standard User. This is modifying a system service, you'll need run the command as an Administrator or with sudo privileges for OS X to accept and process the command.

"I've been able to replicate the error you're getting, when running the command as Standard User. This is modifying a system service, you'll need run the command as an Administrator or with sudo privileges for OS X to accept and process the command."

Unfortunately even logged in as root, I get the same message as NightWing still. Any other suggestions perhaps?

thank you.

Good Morning! Was this ever resolved? I am experiencing the same issue stated above.

I was told by my security team at the college I work at that it needs to be disabled, unfortunately as @NightWing & @mlawrence both stated it won't allow me to do this. I am running into this on El Capitan and only one system at this point. All of my other system have been disabled. Also same thing when trying to MV(rename) /usr/sbin/netbiosd, as sudo or root.

Thank you all for the great comments and assistance. Have a great day everyone!

If on MacOS 10.10.x and above...

Disable netbiosd command

sudo launchctl disable system/netbiosd

Enable netbiosd command

sudo launchctl enable system/netbiosd

The error you were receiving re: service not found indicates the service is not running.
For MacOS 10.9.x and below - your launchctl unload command should be working fine. I have tested this in a postinstall script in a package - works for my systems.

Thank you @mpebley I ran the fix in terminal and it went through without an error. I appreciate all of the assistance. Have a very great day!

I just tried to disable using the code above and it worked, only it requires a passcode. What does that mean and how do I get it? I didn't install this and I want it gone.

See below:
cynthias-MBP:~ cynthiapress$ sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.netbiosd.plist

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

#1) Respect the privacy of others. #2) Think before you type. #3) With great power comes great responsibility.

Password: