WHat happens if you install using a download at http://getthunderbird.com/ rather than doing an update?

Thanks for the response. I can only download from Mozilla since the update function doesn't work (see below). I have tried running the file normally and as Administrator (I am the sole user and Administrator anyway). The message I get in all cases is:

The version of this file is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need an x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher.

My current TBird version is 24.6.0 and is running fine, but I get an update message every day which fails with the following message:

There were problems checking for, downloading, or installing this update. Thunderbird could not be updated because: Failed (unknown reason)

So I cannot update or run a download.

What anti virus are you using?

Malwarebytes Premium ( virus. malware, root kit etc) and ZoneAlarm Extreme Security (inc. firewall). I don't use Windows offerings

Based on something that came up yesterday with update and download blocked in McAfee Enterprise. Check the security software for blocking of Zip files. Thunderbird's installer uses 7-Zip internally (it is a 7-zip executable I think) and McAfee certainly caused exactly the same issues. But it gave a messages about there being a zip.

A quick reboot into windows safe mode with Networking might be the quick and dirty way to see if it is security software.

The McAfee thread is here https://support.mozilla.org/en-US/questions/1040901

Hi Did as you suggested. It came up with the identical Windows message about incompatibility.

I am somewhat stumped here. I run Thunderbird on window 7 pro 64 and it updates every day without issue.

Are you using a machine administrator or a restricted user account?

I have spent some time with google, so we have some further options.

1. Use the Config editor to set the preference pp.update.log to true.
2. Go to the error console on the tools menu (alt+T)
3. clear it.
4. Attempt the update.
5. grab the update URL from the config editor (right click menu) and paste it here.

You might want to paste it into the address bar of your browser to check out what the XML file contains.

While we have always used safe mode with networking here, Microsoft recommends a "clean boot" It truly is a very customized boot, but please try it. https://support.microsoft.com/kb/929135?wa=wsignin1.0

Other suggestions I see from the Google searches are around missing dependencies, but I just do not see any common denominator.

In my version of Thunderbird there is a show update history button in Tools menu > options > advanced > updates. Do you have one? (I am not sure when it appeared but I think it might be post V24) What does it show?