I've made a backup pcv file with MozBackup package (yes, now I know, this software just zips the profile folder, and from now on I surely will do it strongly manually). After reinstalling Windows, I restored TB profile with MozBackup and I didn't see a few subfolders. As far as I know, all the subfolders are stored in the profile like pairs of files (I mean, for example, nnnn.msf and nnnn, the first one is an index file and the second one doesn't have any extention and it contains the emails itself) So, I looked up into PCV file and I found that there are only .msf files (of disappeared subfolders) remain in the archive. Now I'm afraid I've lost emails from those folders permanently. Some configurational details: my operating system is Win7 (64bit), mail protocol is pop3, the size of my TB profile folder is over than 4Gb, recently I've upgraded TB to version 31. Why is it happen? How could it be? Is it possible to restore those subfolders and emails? Any thoughts are greatly appreciated.