Firefox 3 sports a better bookmark manager and is supposed to render web pages more quickly than Firefox 2. The current release of Firefox 3 is in beta but decent enough for you to try it on your computer.
So if you are ready to take the plunge but do not want Firefox 3 to mess-up with your current browser settings, here’s a very safe route for running the new Firefox 3 alongside your existing Firefox 2 install.
1. Download the Firefox 3 Portable edition from – Sourceforge.net.
2. Extract this Firefox 3 installer to some new folder like C:\Firefox3
3. Close your Firefox 2 browser and run the FirefoxPortable.exe file available in the above folder. That’s it.
For additional safety, you can consider creating a backup of your existing Firefox 2 profile that’s available in the following path under the name xxx.default
C:\Documents and Settings\<name>\Application Data\Mozilla\Firefox\Profiles\
And even with release 3, your Firefox Passwords are still not very safe.
Related: Speed Up Your Slow Firefox