I dual boot Win10 and Zorin Linux 17.1, and run Tbird on both of them, works great! I copied my profile directory from Win10 to Zorin, and then renamed it to the name of the profile directory that the Tbird installation on Zorin had chosen. So both systems access the same 10 IMAP email accounts. I keep messages locally, so the profile uses a fair bit of disk space on both systems. In fact, the profile originally came from a different Win10 machine, so I had to copy it to a (large) thumb drive. And that took several hours and encountered numerous problems. The structure and content of the profile directory tree is bewildering. But despite the errors that caused a few thousand items (of the 302,000) not to get copied, it seemed to work just fine(!). It turns out that Zorin seems able to read and write NTFS filesystems quite well. So now I'm wondering if I can copy the profile directory from Zorin to the Win10 partition on the same machine, and replace it with a symlink to that NTFS directory? Does Tbird do funky low-level things to the profile that might not work as expected with Zorin accessing it on NTFS? There would be no risk of race conditions since only one system can be booted at a time. It's just the problems I had copying to the thumb drive in the first place that make me worry that Tbird does some kind of magic with the profile that might not work with linux accessing NTFS... I guess I'll go ahead and try it (and report back here), but I'm wondering if I should expect problems. Thanks!