I want to see what the original ending is like, so I am trying Fallout 3 again

Broken Steel is the DLC I want disabled, right? Or do I need disable all of them?

About disabling... I have gone through Nexus AND the steam launcher to disable them, but as I leave Vault 101, I still get the Broken Steel message.

Now, I am using the Updated Unofficial Patch and FOSE. Will these not allow me to disable Broken Steel? I think I recall, but I'll have to look again, that there is an Updated Patch version for non-DLC games.

Or, should I go with a fresh install sans DLCs?