The HP SimplePass Identity Protection add-on may need to be updated to work with Firefox 4. You should contact HP to see if they have an update for Firefox 4, or if none what their plans are for updating the add-on.

There will be no upgrade- from the company who created the bioscanner for HP:

"Thank you for contacting DigitalPersona. There will be no update releases for DigitalPersona Personal in the future. There will be no updates for Firefox 4 nor Internet Explorer 9. IF they work they work, if they do not work with DPPersonal, then you will have to decide to either keep DPPersonal and forgo Firefox 4 or IE 9, or vice versa. DigitalPersona is leaving the consumer market and is focusing on business applications. In fact, DigitalPersona Personal will not longer be supported after Mid-April of this year. We apologize for any inconvenience this might cause. Sincerely, Tech Team "

As such, I am uninstalling FF4 and going back to 3.6. I like it, but I like the other feature, and I refuse to use IE.

You could try this extension and see if it works.
https://addons.mozilla.org/en-US/firefox/addon/fingerfox-se/

http://amews.net/products/fingerfox/

I know how to remove Firefox 4.0 but how do I install 3.4 or the version that was there previously?

To downgrade to Firefox 3.6 first uninstall Firefox 4, but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data.

You can then install the latest version of Firefox 3.6 available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc.

To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations.

For details of how to find your profile folder see https://support.mozilla.com/kb/Profiles

Well I found a way to make it work on a different post for the same question

http://www.egistec.com/websitedownload/patch/bioexcess/HPSimPlePass7.0.74.0.zip

The only bad thing is you will have to write down all your passwords and log ins because when you install the program it removes the old version :( It also is set up a bit different than use to be but at least it works right

found this info [[|http://support.mozilla.com/en-US/questions/808105#answer-173165]]

Does anyone have any solutions that will work for someone using Windows Vista 64? I've tried the Simple Pass program but it didn't work, I think because it is a Windows 7 version...