This is what have happened:
I have a complete backup from Wednesday 16.11. (Which is running fine)
I also have a file backup (Only a copy of the SQL folder and files etc) from Friday 18.11.
I've tried to stop the SQL server, manually copy the files from friday and start the SQL again.
First I got a error message when trying to start the SQL Server after done this, but after changing permission for the folder it's now starting nicely.
However, there seem to be some sort of password issue as I'm getting:
2016-11-20 12:03:34.51 Logon Error: 18456, Severity: 14, State: 38.
2016-11-20 12:03:34.51 Logon Login failed for user 'NT AUTHORITY\SYSTEM'. Reason: Failed to open the explicitly specified database 'System0001'. [CLIENT: [url removed, login to view]]
This is urgent so hopeing it can be fixed today.
Just ask if you have any questions.