...reverting to 2.0.0.16? Yesterday I encountered big problems after an auto-update of Firefox to version 3.0.1.

Any attempt to remove items from my bookmarks resulted in a total machine hang up.

I tried a system restore to get back to the version 2.0.0.16, but Firefox didn't then work. I removed it through 'Add/Revomve Programs', and then downloaded and installed 2.0.0.16 again. That didn't work.

I went to the Help Forum, and found a recommendation to try installing the older version in a different directory. At last it's working.

(a) How can I ensure I don't get this auto-update happening again?
(b) Why does using a different directory name make any difference?

My Operating System is Windows XP SP2 Home Edition.

It's to do with registry entries. Firefox 3 works well, but finding your bookmarks appears to have caused a problem. It sounds as though you got the automatic update through the Microsoft updates server (Uncle Bill wouldn't sabotage a rival product would he?)

Go to the Firefox site and download the Version 3 installation file. Use Add/Remove programs to remove your existing Version 2. Now look for both old and new program directories and delete them. Go into C:\Documents and Settings and find the Application Data files for Firefox and delete them. If you have a registry cleaner, run that to kill off any orphan entries. Now do a clean install from the file you downloaded. It's worth the effort.

your computer sounds like crap.maybe time to upgrade

To remove items from the bookmarks menu, go to -
My Computer > C:/ > Documents and Settings > [yourcomputername] > Favourites

You can't go back to the old one - just keep 3, it's fine.

Your problem has absolutely nothing to do with registry or which directory it's installed in. You just have to do it the way I have told you.

click tools then options and then high light Advanced and choice the update tab and then put a dot into Ask me what i want to do - under When updates for Firefox are found.