How to Run Firefox 2 and 3 at the Same Time

Here’s a quick how to on running Firefox 2 and 3 at the same time under Windows

1. Right click the shortcut of the Firefox 2, click "Properties". Add "-profilemanager" at the end of the shortcut path. Click OK. Then run this shortcut to launch Firefox Profile Manager.
2. Create a new profile, name it "firefox3". And uncheck the "Don’t ask at startup"
3. Go to Properties of the Firefox 2 shortcut again, remove the "-profilemanager" and add "-p default" at the end of the path. This forces Firefox 2 to open the original profile.
4. Install Firefox 3. Choose "Custom" when you are asked.
5. Change the installation folder to "Mozilla Firefox 3"
6. Same in Start Menu Folder name.
7. When is complete, uncheck the "Launch Firefox now". You still have something to do before you can run it.
8. Go to the Properties of the Firefox 3 shortcut. Append "-no-remote -p firefox3" to the Target. The "-no-remote" will let Firefox run a separate instance. The "-p firefox3" will force your Firefox 3 to run the newly clean profile.
9. Run the Firefox 3, and you will be prompted that your Firefox is not the default browser. DON’T click Yes. Firefox 3 is not stable and you won’t like to use it as your default browser. Simple uncheck the "Always perform this check when starting Firefox" and click No.
10. Now you can run Firefox 2 and Firefox 3 at the same time.