Can I have my Thunderbird email account on my desktop computer and on my laptop simultaneously?

Yes, you can do that. Try this - it preserves your whole existing setup: Install TB on the laptop, then start setting up the new profile: - on the 'Set Up Your Existing Email Address' screen, enter name and email address only - click the 'Configure manually' link - scroll down and click 'Cancel' > Exit setup Copy the TB files from the PC: - launch Thunderbird on the PC - go to Thunderbird menu > Help > Troubleshooting Information - click the Application Basics > Profile Folder 'Open Folder' button - the profile folder will open; navigate three levels up to the Roaming folder - close TB, then copy the Thunderbird folder to a flash drive Paste the TB files to the laptop: - go to the new PC's Roaming folder as instructed above and delete the Thunderbird folder - paste the Thunderbird folder from the flash drive to the laptop - launch Thunderbird