This was more than 15 years ago. We migrated a bunch if data (home to a new server and repurposed the old one, the same night. This was not the first task on that allweekender, so it was around 3am on Sunday, with very little sleep, when I had to copy the data. I did that by logging in as admin and copying with Total Commander. Obviously, even admin did not have the permissions to some folders, so a lot of financial data were lost, as the users found out on Monday morning. We had no backup. Old server was not only reformatted, but the disks were used to build a different raid set. Luckily, one of the users who had access to this data kept a backup on a flash drive. (If you're wondering, I should've used robocopy with backup mode)