Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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
Solved Archived

how do install both 3.6 and 4.0 on different profiles?

wh

I have FF 4.0. I would like to keep up with it as it improves. In the meantime, 3.6 was faster switching tabs and loading most sites. How do I load FF 3.6 and put it on a different profile.

I have FF 4.0. I would like to keep up with it as it improves. In the meantime, 3.6 was faster switching tabs and loading most sites. How do I load FF 3.6 and put it on a different profile.

All Replies (1)

Chosen Solution

Do a custom install and install each version in its own program folder to use multiple Firefox versions.

Create a new profile exclusively for each Firefox version and create a desktop shortcut with -P "profile" appended to the target to launch each Firefox version with its own profile.

See these mozillaZine KB articles for information: