When it comes to computer repair, the most common problem I find is browser corruption. Malicious web sites with infected flash ads are the most common way a browser can get corrupted. So here's how to clean up and reset Mozilla Firefox.
In the past I've shown how to clean up and reset Google Chrome(#1 browser) and Internet Explorer (#2 browser), so this article shouldn't be any surprise. What might surprise you is that I actually have all three browsers installed on my personal computer and Firefox is my default browser. Each as their pros and cons, but the Mozilla Foundation is a non-profit organization and I've always been a supporter of the open-source community.
I've always thought of Mozilla Firefox as a cross between Internet Explorer and Google Chrome, having the best elements from both. Case in point is the way you can access the options in Firefox. You can either use the Menu button in the upper right-hand corner (the button with three (3) horizontal bars) or enable the Menu Bar on top of the browser window (similar to Internet Explorer).
To get the Menu Bar, just right-click the blank area above the Address Bar and select Menu Bar. And there are options that can only be accessed by using the Menu Bar, but I'll talk about that later in this article.
Let's start off with the basic options. If you're using the Menu Button, select Options; if you're using the Menu Bar, select the Tools pull-down menu and then Options. This will bring up the Firefox preferences. On the left-hand side is a menu with several selections; General Search, Content, Applications, Privacy, Sync and Advanced.
When you click on General, you are presented with the most basic settings. If Firefox is been modified by a malicious piece of malware / adware, you'll want to check the When Firefox starts settings to make sure that it's not opening up malicious web pages when it starts up. You can reset it back to the default settings by clicking on the Restore to Default button right below the Home Page box. One of the default settings on this page that I always change is the Downloads option. I prefer to be prompted on where to save a download, as I don't always want them just dumped into my default downloads folder.
The next selection on the left side menu is Search. This is where you can add or remove the search engines that Firefox uses.
You can change the default search engine here or you can change it on the fly by clicking on the magnifying glass on the left side of the Search box. At the bottom of this page you'll find a button called Restore Default Search Engines that does just that.
The next selection on the left side menu is Content. You want to make sure that the Block pop-up windows box is checked. And you may want to click on the Exceptions button and see if there are any websites that you do not recognize. If there are, just highlight the entry and select Remove Site. If you want to get rid of all of them, click on Remove All Sites.
The next selection on the left side menu is Applications. Here you can choose what happens when you choose different actions, like when you click on a mailto: link. Nothing really out of the ordinary here. I would just review them to make sure everything looked good. If you think something is questionable, just change the action. You can always change it back if doesn't work the way you want it to.
The next selection on the left side menu is Privacy. On the top of this page you can select whether to allow tracking cookies or not, it's your choice. One setting I modify on this page is under History. If you pull down the selections under Firefox will: and select Use custom settings for history, you get a few more options. I recommend that you check Clear history when Firefox closes box and then click on the Settings button.
In the window that appears, you can choose what items you want Firefox to delete when it is closed. I personally deselect everything but Cache. But this is strictly a personal preference.
The next selection on the left side menu is Security. Here you want to make sure that Warn me when sites try to install add-ons, Block reported attack site and Block reported web forgeries are selected. You can also change whether passwords are saved and change them if you allow Firefox to save them. You can also add another layer of security for your saved passwords by using a master password.
The next selection on the left side menu is Sync. This a pretty cool feature if you have Firefox installed on multiple devices. I use this feature with a couple of computer and a smartphone. I love the way it will sync saved password across all of my devices. Enough said.
The last selection on the left side menu is Advanced. Here you'll find five (5) tabs; General, Data Choices, Network, Update and Certificates. There isn't much here that needs to be reconfigured, since the defaults are fairly 'run of the mill' kind of stuff. The one exception might be under the Network tab, where you can clear the current web page cache. If you use the clear history setting mentioned earlier in this article, the cache will be deleted when you close Firefox. But if you really need it cleaned immediately, this is where you go to do it.
Now that we've checked and reset and/or changed the preferences, let's take a look at the add-ons page. To get there just click on the Menu Button and select Add-ons. If you're using the Menu Bar, left-click on Tools and select Add-ons from the drop down menu. Once you have the Add-ons page up, you will find five (5) selections on the left side menu; Get Add-ons, Extensions, Appearance, Plugins and Services.
The first selection is Get Add-ons and as the name implies, this is where you can search for and install add-ons for Firefox. Pretty simple.
The second selection on the left side is Extensions. This is where you look for malicious apps that like to run inside of Firefox. Go through the list here and if you find one that you don't remember installing, just click the Disable button on the right hand side.
You be prompted the restart Firefox to completely disable it. Remember that even if you disable an extension, you can always enable it at a later date. Or if you find you don't need it at all, you can always delete it. But remember that if you delete an extension and then realize you really did want it, you will have to reinstall it.
The next selection on the left side menu is Appearance and this is where you change the look of Firefox. If you don't like the default theme, you can always download a new theme under Get add-ons.
The fourth selection down the left side menu is Plugins. Plugins add support for different types of Internet content, like PDF files and Flash content.
One thing you can do here for security is change Shockware Flash from Always Activate to Ask to Activate. In fact, you can do that with any plugin that you're not sure you want to automatically run.
The last selection on the left side menu is Services. These are usually service add-ons, like Facebook or Twitter and they require personal information like usernames and password to use them. If you have any services installed, double check the information you used to set them up.
Now if after going through the previous steps and Firefox is still not working the way it did when you installed it, there are two (2) things you can do. You can either do a reset or uninstall / reinstall. Normally a reset will fix about 90% of problems with Firefox, but there are times when only an uninstall/reinstall will work. I always try a reset first.
To reset Firefox, you will need to have access to the Menu Bar. To get the Menu Bar to appear, just right-click the blank area above the Address bar and select Menu Bar from the context menu. Once you have the Menu Bar, left-click on Help and then Troubleshooting Information.
When the Troubleshooting Information page appears, click on the Refresh Firefox button on the right side of the page. You will be prompted on how you're about to reset Firefox back to its default settings. Click on Refresh Firefox and Firefox will be reset back to its original default settings. It also creates a folder on your desktop called Old Firefox Data just in case you need to restore anything, like your bookmarks.
Now if that doesn't get Firefox back to normal, then the last resort is to do an uninstall / reinstall. This may take a little time to perform, but if you really want Firefox back to pristine condition, this is what it might take. First thing is to go into the Control Panel and select Uninstall a program (if viewing by category) or Programs and Features (if viewing by icons). Highlight Mozilla Firefox and then select Uninstall.
Once Mozilla Firefox is uninstalled, restart your computer. When your computer is restarted and you are logged back in, you will need to remove any traces of Firefox prior to reinstalling it. There are two places that you will need to look for any leftover files, inside your user profile and inside of the Program Files directory. The files inside your user profile are hidden by default, but you can get there quickly by bringing up a Run dialog box (Windows Logo key + R) and typing or copy / paste the following code:
This will open the File Explorer to the location of your Firefox user profile settings. If there is a folder named Firefox, go ahead and delete it. Next you will have to navigate to the location of the Program Files directory and check under the folder named Mozilla Firefox. Its location is usually C:\Program Files (x86)\Mozilla Firefox, but may be different if your version of Windows is 32-bit (C:\Program Files\Mozilla Firefox) or if you installed Firefox on a different drive. Once you get there, if you find a folder named Mozilla Firefox, go ahead and delete it. Now you can download and reinstall Mozilla Firefox.