Advice 1 - always keep a backup Advice 2 - what happened to the original recordings? If you used a hard disc drive camera and haven't used it much since, then the files are probably still on the camera even if you erased them. "Erasing" simply unlocks the drive space and allows the files to be overwritten when needed. So, unless you have used the camera a lot, the files might still be there, Use a programme like recuva to retrieve them. Advice 3 - in future, burn the DVDs before erasing the original recording. Advice 4 - if you are using a networked school computer, there could be a master backup of all users' data. (If it was a home computer that's a big mistake for all sorts of reasons). Calming words - **** happens. You'll get a nasty report from your moderator. I'm sure you won't be the only person this happens to this year.The students should not be penalised BUT there is no corroboration for your practical marks. Shared experience - I lose things too - my hard drive "fried" last week (but I have backups). Hope the tech guys can help you.