When clicking on "Tools", then "Options", all the tabs open except "Options" where I can change font and color.
When clicking on the "Tools" pull down list, then "Options", it gives 8 different tabs. The "Options" will not open where I should be able to change font and color.
Opaite Mbohovái (1)
Try the Firefox SafeMode.
A troubleshooting mode, which disables most Add-ons.
(If you're not using it, switch to the Default Theme.)
- You can open the Firefox 4/5/6/7 SafeMode by holding the Shft key when you use the Firefox desktop or Start menu shortcut.
- Or use the Help menu item, click on Restart with Add-ons Disabled... while Firefox is running.
To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before using the Firefox shortcut (without the Shft key) to open it again.
If it is good in the Firefox SafeMode, your problem is probably caused by an extension, and you need to figure out which one.
http://support.mozilla.com/en-US/kb/troubleshooting+extensions+and+themes