Yahoo seems to have been forced

After installing pdfCreator 0.9.9 (MS WXP SP3), with option "do not install Yahoo toolbar", I have the following in Mozilla Firefox:

1) Yahoo toolbar displayed

2) Yahoo search engine forced

What have I to do, to be able to use a different search engine, as I prefer?

Thank you.

Have you disabled both check boxes?

Problem solved after uninstalling pdfforge toolbar.

In effect I had disabled this installation, but it has been forced. Why?