Without a provided site link no one will know what your asking about nor seeing what is happening.

Trying to go to maps.google.com results in Firefox automatically adding www and changing the target web address to www.maps.google.com

Not really sure how saying it's automatically adding www. onto the front end of all web addresses that don't use it is not enough info. It's been an issue off and on for years and the latest update made it an issue again. All previous disabling methods no longer work.

So in a bit more detail:

• If you click a link to https://maps.google.com/ does that work normally?
• If you paste that full URL into the address bar and submit it, what happens?
• If you only paste the hostname portion without the protocol -- maps.google.com -- and submit that, then Firefox adds www to the front?

I assume you've restarted Windows at least once since this problem started and that doesn't help.

Could you check Firefox's connection settings here:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the search box at the top of the page, type proxy and Firefox should filter to the "Settings" button, which you can click.

The default of "Use system proxy settings" piggybacks on your Windows/IE "LAN" setting. "Auto-detect" can lead to a flaky connection. You may want to try "No proxy".

Any difference?

Could you test in Firefox's Safe Mode? In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Hi, Be careful the change may effect Sync If you do not use it will not matter.

Try this one 1st : In the Location bar, type about:config and press "Enter" The about:config "This might void your warranty!" warning page may appear. "Click I'll > be careful, I promise!", to continue to the about:config page.

• In the Search field, type "browser.fixup.alternate.enabled"

Double-click the "browser.fixup.alternate.enabled" preference to set its value to false.

Restart Firefox, if this works, stop there. If does not work, reverse it.

In the Location bar, type about:config and press "Enter" The about:config "This might void your warranty!" warning page may appear. "Click I'll > be careful, I promise!", to continue to the about:config page.

• In the Search field, type "browser.urlbar.autocomplete.enabled"

Double-click the "browser.urlbar.autocomplete.enabled" preference to set its value to false.

Restart Firefox to test,

Remember what you did.

Please let us know if this solved your issue or if need further assistance