You might want to try Firefox's safe mode to find the problem. You may need to restart your computer first to get rid of the old process.

How do I open Firefox in Safe Mode when it will not open at all? I can't get into it. I have rebooted several times to no avail. I have downloaded the program again. It just will not let me in.

In my own experience with FF, I've come to learn to remove all previous versions of Firefox before going to the next version. That way you get a fresh start with the new version and you minimize the chances of older features, settings, cache, cookies, etc, from contradicting or conflicting with the new version's. It's not the most practical way to go about it because of the saved passwords and bookmarks in the version being replaced. You would have to get a print-out of the bookmarks and passwords to enter into the new version. I'm talking about going from FF3 to FF4 to FF5.... Anytime the version # changes, there is significant overhaul or version remodeling. But if you don't remove the older version, which Firefox should do automatically, somehow, then you would experience discrepancies with even the most basic features. I see Jevanstar replied to you with a safe mode link, but you're still asking how to. Click on that link and it will take through on how to.

Thanks JorgeP and jevanstar for you response to my problem. I really appreciate it. This is my first time using this method of problem solving. Glad it is available. I tried to access the SafeMode with the instructions you provide. When clicking on the Mozilla program in the list, surprisingly there was not a drop down for Safe Mode! There is one on my desktop, but not the problematic laptop. Don't understand that. Apparently, no way into SafeMode. Next, I attempted ot uninstall Firefox. It would not allow it because the message said that the program was running, although there is no evidence that it is. Next, I decided to go back to an earlier date and do a Restore. First, I tried two days prior to the problem. Restore said that it could not restore due to an error. Nothing changed. I then went back to a month previous and attempted to restore, but alas, the same problem with restore. Yesterday, I carried the laptop (Gateway, several years old by the way, but had been working beautifully), to a friend in the computer repair business for a check up. If anyone has an idea, let me know.

FF5 ran once after installation but now it will not load. The process - firefox.exe *32 - loads but the application does not open. I did try the sync extension but that failed to sync due to a wrong ID number entered.

I have uninstalled and reinstalled FF5, but no luck. I'm running Win 7, 64 bits.