This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Can I install FF 4 RC and keep FF3.6.15 installed until I check out the RC?

more options

I'm running FF3.6.15. I want to test FF 4 RC. Can I install the RC while keeping 3.6.15 on my system temporarily?

I'm running FF3.6.15. I want to test FF 4 RC. Can I install the RC while keeping 3.6.15 on my system temporarily?

Chosen solution

You're welcome.
Please click the Solved button next to the answer that solved your Firefox support issue.

Read this answer in context 👍 1

All Replies (4)

more options

When you install a release candidate it will be default replace the previous version. To stop this from happening use the Custom installation option and specify a different location to install Firefox 4.

If you want to use both versions, you need to create a new profile for Firefox 4 (Firefox stores user data in the profile). Using the same profile with different versions can cause problems. Once you create a new profile you can copy certain data such as bookmarks and passwords between them. You can also use Firefox Sync to keep the profile synchronized. Finally, you will need to set up shortcuts to launch the correct profile for each version.

The following links show how to do this:

more options

You could use the Firefox Portable edition and install it to your hard drive, which would automatically be completely separate from any other version of Firefox you have installed, including the Profile.

The 4.0RC version should be available the same day as the RC version is released by Mozilla, but usually later in the day or the following day.

http://portableapps.com/apps/internet/firefox_portable/test

more options

Thank you TonyE & the-edmeister for the feedback.

more options

Suluhisho teule

You're welcome.
Please click the Solved button next to the answer that solved your Firefox support issue.