It can happen when you install ISP software, or if you get a pre-built computer from somewhere. You’ll see something like the next screenshot (Notice the “Some ISP Title” in the title bar)
To remove this ridiculous nonsense from either IE6 or IE7, you can just open up the registry, and browse down to the following key:
Once there, you should see a string value called “Window Title” in the list, with the offending text.
Just hit the Delete key to remove it, and spend some time cursing the company that made you go through this trouble. You’ll have to close all open Internet explorer windows, but when you reopen them, that text should be gone.