If you are here, you must be having some kind of problem with Firefox. The main thing to remember is not to panic--most problems are caused by something very minor.
The first thing to do in order to find out what is causing the problem is to shut down Firefox and restart in Safe Mode. To do this in Windows XP, go to Start, Programs and click on Firefox (Safe Mode). This procedure starts Firefox without any extensions, and only the default theme. If, after starting, the problem no longer exists, you can surmise that it was caused by an extension or theme that you installed. If this is the case, you can disable all themes and extensions and add them back, one-by-one, until you find the one causing the problem.
If the problem persists, I recommend making a new profile. This doesn't mean that you have to delete your old profile--you can actually make a new one very easily. To do this, right-click on your Firefox icon and select "Properties". In the Target window, you will see a string similar to this: "C:\Program Files\MozillaFirefox\firefox.exe" After the firefox.exe" space over one space and type -p so that it looks like this: "C:\Program Files\MozillaFirefox\firefox.exe" -p. Close the property dialog box and click on the same Firefox icon. The profile manager will give you the option to create a new profile, delete a profile, or select another profile. Create your new profile and open Firefox. If this solved your problem, you had a "borked" profile. You can now begin to set this profile up by installing extensions and themes, etc.
Hint: You can have one Firefox icon devoted to being the Profile Manager. Rename this icon to Profile Manager and access by clicking on its icon. When you want to start Firefox, just click on another Firefox shortcut. I have two Firefox icons on my desktop: one is the standard icon and the other is labeled "Profile Manager".
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