I presume you are trying to download a current release version from the official webpage: https://www.thunderbird.net/en-US/thunderbird/all/

It's possible you have Anti-virus software that is not allowing the download, so start computer in 'Safe Mode with Networking' mode to get the download and auto install.

Then restart as normal. Then check your Firewall allows Thunderbird to use the internet. Mozilla thunderbird must be an allowed program otherwise it will not be able to connect to servers to access mail.

I did not have any problem downloading I just can't log in

so you can install it and can not configure your accounts. Is that right?

If so see Toads answer... the anti virus is still the most likely issue.

re : I just can't log in

I presume you are trying to create a mail account and failing. Please confirm that Thunderbird is an allowed program in your Firewall. The 'Firewall' may be part of your Anti-virus program. This must be set up otherwise Thunderbird cannot access internet. Q: Is Thunderbird an allowed program in the firewall?

If you use ESET then read this and alter settings: If you are using ESET/NOD32 security/AV then probability is very high it is causing your problems. According to their forums, you should temporarily disable SSL until they solve the problem per https://support.eset.com/en/kb3126-disable-ssl-filtering-in-eset-windows-products?ref=esf - the problem is being reported by dozens of users https://forum.eset.com/topic/26517-problems-with-thunderbird-and-imaps/ https://forum.eset.com/discover/

Are you sure the password is correct? To prove this, logon to your webmail account via a browser. If you get access then you know the password is correct. This would then be the same password you enter for that mail account Thunderbird. Q: Can you access the webmail account - yes or no ?

You do not mention whether you are trying to create a pop or imap account. Q: Are you trying to set up a pop or an imap mail account?

TWC is handled by Spectrum.

• Incoming Email Server: mail.twc.com
• IMAP uses port 993
• Connection Security: SSL/TLS
• Authentication Method: Normal Password
• User Name = full email address

• Outgoing Email Server: mail.twc.com
• Port: 587
• Connection Security: STARTTLS
• Authentication Method: Normal Password
• User Name = full email address

I did not have any problem installing TB imap account I have it on my other two PCs. I do not have any problem accessing my web account I tried using the same password for the TB account but it doesn't work. I keep getting the message that log in failed add another password.