Clean Reinstall of Firefox 3

In order to solve a problem with Firefox 3, I had to do a "clean reinstall" of Firefox 3, not just uninstall and reinstall.

The steps were:

Export the Firefox 3 bookmarks
From the toolbar, Bookmarks > Organize Bookmarks > Import and Backup > Backup...
pick the location and file name to save your bookmarks for importing into Firefox later. Save them somewhere in My Documents or elsewhere of your choice — just not in the Application Data\Mozilla\FIrefox folder The filetype will be .json.
Just in case, make a different type of backup, also.
Bookmarks > Organize Bookmarks > Import and Backup > Export HTML..., which will create an HTML file of the Bookmarks. If I recall correctly, this is the file that worked for me. I think I had problems with the .json file
Uninstall Firefox:
Start > Add or Remove Programs > Firefox > Uninstall (or Remove, whichever it says)
Open Windows Explorer: Right-click on Start > Explore
If you have not already done this, set Windows Explorer to Show Hidden Files and Folders
Move to C:\Documents and Settings\[YourUserID]\Application Data\Mozilla\Firefox
Either (a) delete the Firefox directory or (b) rename the Firefox directory to something like Firefox-old
Reboot
Install Firefox
Now import your bookmarks that you saved: If I recall correctly, importing from the saved HTML file seemed to work, while importing from the .json file (the "backup file") didn't work right.