when I start fire fox i get the My Start Incredibar browser instead..
It sounds like you have a Third-Party Toolbar that has taken over your Search Engine, Home Page, and/or the Default New Tab Page. Fortunately this can be remedied easily:
After Firefox restarts, install the Search Reset Tool. This will remove the rest of the traces of this program from your Firefox.
For further information, please read Remove a toolbar that has taken over your Firefox search or home page.
Does this help your question? Let us know!
See also these pages: