http://support.mozilla.com/en-US/kb/Installing+a+previous+version+of+Firefox

The 4.0 beta versions install in a separate program folder, so you should still have the Firefox 3.6.x version installed. You can take a look or do a search in "C:\Program Files\" (Mozilla Firefox)

How do I find C Program files. I went to Add and Remove programs and only FF4 is there FF 3.6 is gone from the control panel.

Not just the toolbar! Too many bugs in Firefox 4 to even count. Every day I run into more and more trouble. I will keep the rollback as long as I can. Then if Firefox has not fixed the problems I will choose a different browser.

The Google Toolbar extension is known as problematic in multiple versions of Firefox, not just Firefox 4.

wtherrell, it is more of a problem of the various toolbars not supporting newer major Releases (either right away or bug free), not the other way.

Norton for example is a big problem with this.