1.) Which browser are you using? It should have the ability to remove the Yahoo tools directly.
2.) Have you looked in Add/Remove Programs via the Control Panel? The Yahoo toolbar is generally installed as a Windows application, so you can install it as such.
P.S. Never delete registry entries as a first attempt; it can cause the normal uninstallation process fail, leading to greater removal issues.
I have somehow managed to get a Yahoo item in my menu bar and a yahoo toolbar. I have deleted everything in my registry dealing with Yahoo, yet they remain.
I don't use yahoo and everything in the menu and toolbar is redundant.
Besides, I just plain don't like it when some program takes control of my computer. It's my dang computer. I paid for it.
I asked yahoo support but of course they ignored me. Just another reason to get them off MY computer!!!