At the top right of the Thunderbird window, click the menu button > Options > Advanced > General > Config Editor.

Promise to be careful.

Type 'printer' in the search field (without the quotes). This will bring up all printer related preferences.

Right-click the ones you want to get rid of - Reset. It will probably take a while.

I tried your suggestion, but no printers showed whenI typed"printer" without the " marks.

Any other suggetions.

At the top right of the Thunderbird window, click the menu button , then select Help > Troubleshooting Information.

I'm certain you'll see printer related prefs.

Nope. Not there. See below.

 Application Basics

   Name: Thunderbird
   Version: 38.4.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20151119061742
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) mail.iserv.net:110, plain, passwordCleartext
     OUTGOING: mail.iserv.net:587, plain, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

 Crash Reports

 Extensions
   Lightning, 4.0.4.1, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.smart_size_cached_value: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     browser.display.use_document_fonts: 0
     extensions.lastAppVersion: 38.4.0
     font.name.monospace.el: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Arial
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.serif.el: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Arial
     font.size.fixed.el: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 17
     font.size.variable.el: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 20
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: 569f6e7e-2d26-42d2-86c5-a498d8e80f8
     network.cookie.lifetimePolicy: 2
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1448991283
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true

 Graphics

     Adapter Description: Intel(R) HD Graphics 4600
     Vendor ID: 0x8086
     Device ID: 0x0412
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
     Driver Version: 10.18.15.4256
     Driver Date: 7-17-2015
     Direct2D Enabled: false
     DirectWrite Enabled: false (10.0.10240.16430)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: cairo

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.10.10
     4.10.10

     NSS
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

     NSS Util
     3.19.2.1
     3.19.2.1

     NSS SSL
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

     NSS S/MIME
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

in windows start menu search thingy use the term printers. or go to the control panel and look at the devices and printers section

I think you will find your removing the applications from the application control panel, but not the actual printer drivers from the printer pane in Windows.

No printers show on "devices and settings" which is new term for part of the old control panel?

PullingHairOut said

No printers show on "devices and settings" which is new term for part of the old control panel?

I think in XP is was just printers... but time has eroded my memory somewhat.

use the config editor and search on the term printer... is there any of your unknown printers showing up?