Disappearing e-mail is a terrifying thought to many of us. And it happened to one of our readers. Roy from the U.K writes: I had my PC upgraded from XP to Windows 8. The technician said he kept my data but now I can’t find any of my Thunderbird emails from before the upgrade date. I have tried to find them with searches and so on but no luck. Where did they go?

Much like your Windows user profile that you log into whenever you boot up your computer, Mozilla sets up user profiles for both the Firefox browser and the Thunderbird email client. Most people don’t even notice these profiles, because Thunderbird simply creates a default profile when you install the program, and unless you had cause to create a new profile or delete the default one, its unlikely you would even be aware of its existence.

This can cause a problem when you upgrade to a new operating system like Windows 8 however, as Windows stores the old profile in a separate location and a new one is automatically created. All your messages are still there, they are just stored in a separate folder containing all the data from your old profile.

Hopefully it hasn’t been too long since you upgraded however, as Windows only saves your old data for 28 days after upgrading! In this case, unfortunately all your messages are likely gone, unless they are still stored online somewhere by whatever email provider you happen to use.

To swap your messages from your old profile out with your new one, first you will need to change a setting to be able to see hidden files and folders. Open a file explorer window and then click the “View” option in the ribbon at the top of the window.

Viewing Folder Options

Click the “Options” button at the far right side and select “Change Folder and Search Options.”

Folder Options

Navigate to the “View” tab and then scroll down and click the radio button labeled “Show Hidden Files, Folders, and Drives.” Click “Apply” to save the change.

Viewing Hidden Files and Folders

In this file explorer window you’ve already got open, navigate to the C drive and then open the “Windows.old” folder, which contains all your old data from before upgrading. From there, you can find your old Thunderbird profile by navigating to “C:\Documents and Settings\<yourprofileusername>\Application Data\Thunderbird\Profiles” Double click the profile name, which will be a long string of numbers and letters.

Leave this window open, which contains all your old profile data (including your emails), and then open up Thunderbird. Click the menu icon (the image with three straight lines) and then select “Help” and “Troubleshooting Information.”

Troubleshooting Thunderbird Window

Underneath the “Application Basics” heading, click the “Show Folder” button. This will bring up a second file explorer window containing your new profile created after you upgraded to Windows 8.

Thunderbird Profile Folder

Click anywhere inside the profile folder, and then tap “Ctrl” and “A” together to highlight everything. Tap the “Delete” key to remove all your new profile info. Don’t worry about losing that – you’ll be replacing it with your old profile data shortly (although keep in mind you will lose anything you’ve saved or written since upgrading to Windows 8).

Remember that other explorer window we kept open? Return to that and hit “Ctrl” and “A” again to highlight everything. Only this time, we’re not going to delete it – instead, click and drag all the highlighted folders and files over to the second window you just cleared out. This will transfer all your old profile info – including messages – to your new profile. You should now be able to read all your old messages in Thunderbird and retrieve all your old settings and address book entries!

~ Ty Arthur