Have you tried the following?

Menu button > Add-ons > Extensions > Remove button Then you might need to restart Firefox.

See this - http://www.couponsinc.com/corp/source/u_uninstall.asp

still can't remove coupons.com from tool bar or browser even though I disabled them.

Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information.
Note: This will cause you to lose any Extensions and some Preferences.

• Open websites will not be saved in Firefox versions lower than 25.

To Reset Firefox do the following:

For Firefox versions previous to 29.0:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

For Firefox 29.0 and above:

1. Click the menu button , click help and select Troubleshooting Information.

Now, a new tab containing your troubleshooting information should open.

1. At the top right corner of the page, you should see a button that says "Reset Firefox". Click on it.
2. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
3. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.