You can create distinct Firefox profiles for each person. Actually, you can have as many profiles as you like.

To get started:

Create a new Firefox profile

This is in addition to and does not replace your existing settings.

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should come with completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run) -- type or paste the following and press Enter:

firefox.exe -P

Don't delete anything here.

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like His (another new one can be Hers), and ignore the option to change the folder location. Then start Firefox in the new profile you created.

Next, edit your Firefox shortcut so it start up the profile manager. To do that, right-click the shortcut > Properties > Shortcut tab. At the end of the "Target" add the -P and OK the change.

If you use that with Firefox already running, a new window opens. If Firefox is not running, then you get the Profile Manager.

You can choose the profile you want and start Firefox in it.

Does this suit your needs? With a little more work, you can create His and Hers shortcuts so you don't need to use the Profile Manager. (I'll have to look up the steps for that, though...)

Note: If you want to import bookmarks from your regular Firefox profile, here's how:

You can use the Library dialog (Ctrl+Shift+b or "Show All Bookmarks") to access the Restore feature. The trick is knowing where to find your bookmark backups in your regular profile. After clicking Choose File... you can paste this into the file name space and press Enter to drill down to your profile folders:

%APPDATA%\Mozilla\Firefox\Profiles

The semi-randomly-named folder that has your last backup is usually the one ending with "default". Click into that one, then into the bookmarkbackups folder. Here you can pick the most recently updated file to restore.

By the way, the "Updated Ad Blocker for Firefox 11+ 0.7.7" extension is obsolete and Adblock Plus is now much more up-to-date. I suggest removing that older one.

Multifox 2.2.0 No Restart by jhultmann Multifox {web link} Multifox is an extension that allows Firefox to connect to websites using different user names. Simultaneously!

Thank you very much for your rapid and very clear response. It was exactly what I required.