thunderbird does not run without a prefs.js. Maybe if you post a screenshot of the complete profile, some suggestions may be offered. To be sure of the profile, do this: - click help>troubleshootinginformation - scroll down to 'profile folder' and click 'open folder' - you are now in the profile. Do a screenshot of the complete folder and post it. thank you.

Posted screen shot of profile folder content also View Menu showing hidden files are visible. As you can see there is no prefs.js in the folder specified in the Troubleshooting Information/Application Basics/Profile. Any pointers anyone?

Suggestion: - create a dummy file in the profile folder. - then attempt to rename it to prefs.js - my guess is that windows will say that file already exists. I do not understand this, but I know from prior experiences with users having this problem, the prefs.js was not visible. Maybe someone on forum who understands this can explain it.

Your guess is correct. Its because the .js filetype is considered a vital system file. You need to open the folder properties view tab and uncheck the hide system file option. See screenshot. Then you will see the prefs.js. Look at properties and it will be read only. Uncheck read only and now settings will be saved. Once you open the profile folder in explorer make sure you SHUT DOWN TB as it seems that TB might rewrite the prefs file on shutdown hence eliminating the changes you made in explorer. Thanks for your help in getting my engine running !!!

I was glad to assist. And it helps me as well. I have that option set to show hidden files and had not thought of it. So, thanks to you as well for sharing. :)