Here you also have the copy of the Troubleshooting Information if necessary.

 Application Basics

   Name: Thunderbird
   Version: 24.4.0
   User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20140316131045
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Crash Reports: about:crashes
   Memory Use: about:memory

 Mail and News Accounts
   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account4:
     INCOMING: account4, , (imap) imap.googlemail.com:993, SSL, passwordCleartext
     OUTGOING: smtp.googlemail.com:465, SSL, passwordCleartext, true

 Extensions
   bdToolbar, 7.0, false, bdThunderbird@bitdefender.com

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     browser.cache.disk.smart_size_cached_value: 358400
     extensions.lastAppVersion: 24.4.0
     font.name.monospace.el: Consolas
     font.name.monospace.tr: Consolas
     font.name.monospace.x-baltic: Consolas
     font.name.monospace.x-central-euro: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Consolas
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.tr: Calibri
     font.name.sans-serif.x-baltic: Calibri
     font.name.sans-serif.x-central-euro: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Calibri
     font.name.serif.el: Cambria
     font.name.serif.tr: Cambria
     font.name.serif.x-baltic: Cambria
     font.name.serif.x-central-euro: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Cambria
     font.size.fixed.el: 14
     font.size.fixed.tr: 14
     font.size.fixed.x-baltic: 14
     font.size.fixed.x-central-euro: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.tr: 17
     font.size.variable.x-baltic: 17
     font.size.variable.x-central-euro: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 17
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: 8057ef62-d03a-4da8-a08b-58764ba65fd
     network.cookie.lifetimePolicy: 2
     network.cookie.prefsMigrated: true
     places.database.lastMaintenance: 1397398207
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true
     privacy.donottrackheader.enabled: true

 Graphics

     Adapter Description: Intel(R) Iris(TM) Graphics 5100
     Vendor ID: 0x8086
     Device ID: 0x0a2e
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32
     Driver Version: 10.18.10.3345
     Driver Date: 10-31-2013
     Direct2D Enabled: false
     DirectWrite Enabled: false (6.3.9600.16384)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: none

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.10.2
     4.10.2

     NSS
     3.15.4 Basic ECC
     3.15.4 Basic ECC

     NSS Util
     3.15.4
     3.15.4

     NSS SSL
     3.15.4 Basic ECC
     3.15.4 Basic ECC

     NSS S/MIME
     3.15.4 Basic ECC
     3.15.4 Basic ECC

I am marking this thread closed with a solution in one of the many other threads you have created. Please stick to one. I suggest this one. https://support.mozilla.org/en-US/questions/990748#answer-556205

We have uninstalled Thunderbird and install it again several times in the past days with no success

Re-installing TB seldom solves problems, because the problem is in the profile most of the time.

In the past 2 weeks Thunderbird started working only for few hours and we have the same problem again.

That pretty much sounds like a network problem. Verify your Internet connection.

I turned of bot windows firewall and BitDefender firewall

You must not run two firewalls on the same computer.

I remember that I choose not to install Microsoft updates ever.

That's a very bad idea.

I am trying to add Gmail and AOL accounts in Thunderbird.

There already is a Gmail account set-up according to your Troubleshooting Information.

Extensions

  bdToolbar, 7.0, false, bdThunderbird@bitdefender.com

Get rid of this extensions.

The windows 8.1 regular firewall is active. Also i have Bit defender antivirus that probably has his own firewall but i just let the BitDefender as a default installation. I mean that's how I worked for many years now. Is nothing different. I stopped each firewall and the problem with Thunderbird is not solved.

Yes, there is a gmail account at this time in Thunderbird as I had the chance to add it in the single day that Thunderbird worked in the past month. It was a day when I just tried Thunderbird and it was active. was working, but just for few hours.

reporter has gone to https://support.mozilla.org/en-US/questions/990748#answer-556205 so I'm closing this topic.

Anyone still seeing this problem should Start *Windows'* safe mode with networking enabled - win8 http://windows.microsoft.com/en-US/windows-8/windows-startup-settings-including-safe-mode - win7 http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode - XP http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx

Still In Windows safe mode, start thunderbird in safe mode - http://support.mozillamessaging.com/en-US/kb/safe-mode

If problem does not go away then please create a new topic.