Question: How can I get thunderbird to either read the profiles.ini and installs.ini files from a USB stick, or create a work around where they would be created with the correct drive letter in the ini file path that points to the profile directory on any PC where the USB is used to run Thunderbird. Change a setting somewhere in the Thunderbird files, or create a batch file, a script. Anybody has done this before? Background After a recent nightly update Thunderbird got a consistent app crash. Wayne Mervin recommended avoiding version 77 but go version to 79 directly. I had rebuilt my previously flawless portable USB installation with version 68. I thanked Mervyn for the explanation. I used his link but got Thunderbird Setup 68.9.0 from the regular download and Thunderbird Setup 77.0b3 from the Beta-channel which I used before. So I don't know where version 79 is available. Anyhow, as I said i have re-built the USB stick installation but I used version 68.9.0.and have become a bit update shy now. For some reason I cannot get back to what I had before namely a fully portable Thunderbird that I could use on any PC to access my web account and download mails as needed. So I opened another question regarding the workaround needed to have the Profile path and ID containing files profiles.ini and installs.ini that are still required in the directory C:\users/mdw/appdata/local/roaming/thunderbird on the USB stick as well. Either some setting can be used to make thunderbird.exe look for this two ini files on the USB stick, or a routine, script or batch file can be created where the two files are copied into the %appdata% with the ini file values for the profile path containing the USB’s drive letter before launching thunderbird.