when you were installing mozilla did it ask whether it could instal the yahoo toolbar and have you checked in the settings of the browser if you can disable the option

There was no prompt to download the toolbar and to make sure I just finished deleting Mozilla and then reinstalled and it still is opening endlessly. And I can't figure out how to disable it, when r. click on the tool bar the yahoo tool bar is not checked.

This happened to me, and it was a stuck keyboard key that initiated it (it was not a toolbar, but a hotkey someone had installed).

After I fixed the stuck key, the browser windows continued to open, even after the computer was rebooted. But this was because the requests for the pages were still in the server. We had to keep closing the windows until all of the requests were gone.

have you tried another version of mozilla and also check msconfig to see whether it's in the startup items

this from yahoo answers !.
and i quote==
Try starting Firefox in safe mode...click on TOOLS and click on ADD ONS...from here uninstall the Yahoo Toolbar and then close Firefox and restart. You may need to go back and enable your custom add-ons for Firefox from the TOOLS menu.

PROBLEM SOLVED, thanks so much, I just uninstalled the yahoo tool bar and it no more problem, evidently after a search on the web I'm not the only one that has had this problem with YahooBuildToolbar.
Once again thanks
Brant

your welcome ,