You have two choices for installing beta: Option 1 allows you to run the beta alongside the Stable version of Thunderbird, and Option 2 upgrades your existing installation.
- Run Stable and Beta side-by-side (recommended).
Thunderbird 102 and newer on Windows will install beta into its own program directory. For older versions on Windows consult the beta support article. For other operating systems use an install method appropriate for your OS to target a uniquely named directory.
This choice has the advantage of forcing a dedicated profile for each Thunderbird, which allows you to have both the release version and the beta version operate independently. So you can:
- Start the release version of Thunderbird (with beta not running) and it will use the "default" (or default-release) profile.
- Start the beta version of Thunderbird (with release version not running) and it will use the default-beta profile. On first use Thunderbird will create the default-beta profile, and it will prompt you to define your accounts. If you need to bring some data from your release profile into the beta profile, consult the beta support article.
- Upgrade your existing Thunderbird installation to beta.
Simply install beta over top of your current program directory, using the default installer choices. Beta will then use your current (production) default profile. Because it uses your default profile, this choice makes it more difficult to switch back to using a release version should you wish to do so in the future. In other words, you should not switch back and forth between beta and normal release using the same profile.
For very detailed information about both methods, please check the beta support article.