I’ve removed the answer which provided you no useful information at all.
If the SQL Server service is running then you can not backup the folders with the SQL Server databases in them as the files are locked. You have two options.
1. Just before your upgrade backup all the databases using the SQL Server BACKUP DATABASE command. Then backup those backups to tape.
2. Stop the SQL Server service which will cause the database engine to release its locks on the database files and you can then back them up to tape.
Option #1 is the much better option as it doesn’t require that the database be taken offline.