QUESTION; Where do I go from here? NARRATIVE: My C:\ drive (!Tb) started to balk when after I had a little more than 800Gb stored on it. My tech told me the machine case would hold two internal HDs. We bought an additional 1Tb HD and he installed Windows basics, all drivers, and my regular backup utility so we could make an immediate mirror image of the drive on an external HD. Both internals carry Windows 7 64-bit, and by editing Boot Config, I can boot from either -- with no errors or red flags. I downloaded TB 31.0, installed it to the new drive; then copied out App Data and Application Data including all TB files from the old HD (2 Windows User accounts) to discreet folders on an external drive. From there, I copied them to the appropriate folders for the two Users on the new HD. Thunderbird will not access them, even though I have used every workaround and trick I have learned with TB over a dozen years. I've worked on this many days, checked several similar items on the forum, and don't see a solution. (And my tech has never wanted to learn anything about Tbird; nor has he needed to in times past. I have just uninstalled Thunderbird 31.0 and deleted the content under TB folders in App Data (2) and Application Data (2) on the new C:\ drive. I first confirmed that all previous data is available on the old HD and that the copy on the external drive is complete and accurate -- and without any Windows security locks. Local Settings folders on both old-drive/Users were locked and could never access them, but some TB-related files were in there in times past. What should I do? 1) Install an older version of Thunderbird and hope that I can marry the old files in? or, 2) What can you suggest? Many thanks in advance. edj.