Yep that's it.

And you'll be doing that for at least 7 or 8 templates.

This is why I am saying WAIT... Someone more knowledgeable than I will come along and give you a much simpler and easier way.

Because this only removes the button from the editor. IT DOES NOT STOP ANYONE FROM USING THE UNDERLINE FUNCTION ANYWAY. They can still manually input it into their posts.

Oh you're talking about the Underline button in posts?

I'm referring to that image where there's a space and underline before and after the A, and how to remove that.

Please provide screenshot.

Ok... That looks like it is coming from a modification on your site. You should be asking the developer of that Mod about this, in the thread where you found the modification.

I don't think it's a mod, but I can't be for sure since I can't see the Admin CP.

I am sure. The image placed beside the username is not native to vBulletin.

I know, I'm sure they're user ranks.

That underline is because white space is hyperlinked.

e.g. <a href="examplelink">Edia <img src="image.png" alt=""></a> <img src="image.png" alt=""></a></a>

You can use the exmaple code below to remove the underline from white space:

<a href="examplelink">Edia</a> <a href="examplelink"><img src="image.png" alt=""></a> <a href="examplelink"><img src="image.png" alt=""></a>

And where can this be placed?