If its not the hd thats dead you can remove it. If the new pc has room for a second hd and you have the cables to match you might install it that way. Otherwise you might connect it thru an usb-device. If you manage this then your old data should be under: "Drive X":\Users\"old username"\AppData\Roaming\Thunderbird\Profiles\??????.default" Drive X = whatever drive-letter your old hd gets. Old username = your old WINDOWS username ??????.default = random name with usually .default as extension (if its your first TB-profile, otherwise ...) AppData and its subdirectories are hidden so you need to "show hidden files" If your new pc has a fully installed T-bird you might want to import all old mails. Use an add-on [https://freeshell.de//~kaosmos/mboximport-en.html ImportExportTool]