I already discussed this problem in a previous archived article but didn't reach a solution. I am running Windows 10 and the latest Thunderbird (38.7). Thunderbird frequently hangs when performing different tasks, and the problem doesn't seem to be specific to a certain task. When it happens, the hanging goes on for up to 2 minutes sometimes before the task is completed. I tried to operate Thunderbird in safe mode and the problem is still there. I also tried to disable the usual culprit - the anti-virus software (NOP in my case) but the problem still persisted. I now rebooted Windows 10 to safe mode with networking and started Thunderbird in regular mode to see what happens. For the time being it seems to work OK, but I have come across a different problem. When Windows 10 is in safe mode it is impossible to work on the PC as it won't allow programs to open even when selected manually. Examples? All Office 2013 programs, printers, anti virus, etc. On older Windows versions it was always possible to manually turn on programs even when in safe mode so this behavior seems strange. At least it allows me to operate Thunderbird! Any suggestions where to go from here? If I can't turn on individual programs, how do I find out which one is causing the problem?