From MozillaZine Knowledge Base

Portable Thunderbird is a third party build of Mozilla Thunderbird that includes a launcher to let you store your email, address books and settings on the USB drive, along with Portable Thunderbird.

Your profile contains your email, address books and settings. Thunderbird normally finds it by looking in a profiles.ini file on your boot drive. You can have multiple profiles, the file also tells Thunderbird which one to use by default. Portable Thunderbird only supports one profile, which it expects to find in the Data\profile directory within Thunderbird Portable. If you're switching to Portable Thunderbird you just have to find your current profile and copy its contents there [1]. Don't copy the directory too. See this article for how to find your profile under Windows.

If this doesn't work:

• Check that you didn't copy the profiles subdirectory that contains one or more profiles, or copy the profile directory (whose name typically ends with ".default"). You only want to copy its contents, not the actual directory. If you look in the Data\profile directory you should see a prefs.js and a abook.mab file (among other files).

• If Portable Thunderbird has a problem with your profile try transferring only the most important files from your old profile to one created by Portable Thunderbird, per this article.

• You could launch Mozilla Thunderbird with a -profile "path" command line argument that specifies the profiles new location, to verify the profile works, and that you copied all of its subdirectories. If that works, then find Portable Thunderbird's thunderbirdportable.ini file (it should be in the same directory as ThunderbirdPortable.exe) and check that ProfileDirectory=Data\profile and that your profile is stored there.

See also

• Moving your profile folder
• Profile Manager
• Running from a USB drive - Thunderbird
• Thunderbird Command Line Arguments

External links

• Which of my profiles should I import?