A Program occupied all disk space, I didnt noticed. I deleted some emails (tens, hundreds) in Thunderbird and after that I closed Thunderbird. No error message showed. After that I noticed that there is no disk space. I started Thundebird again (still no disk space) and TB look like new instalation, no emails, no email accounts. I freed some disk space, but the problem remains. On the disk seems all data are correct (about 20GB, about 12 email accounts), maybe only some files are corrupted? I have backup a month old. Is it possible some files restore from the old backup? Which one/ones? Or rebuild? Windows 8.1