To Backup a database from command-line and using SQL 2000 MSDE version, you must use the SQLMAINT.EXE file situated in the ‘C:\Program Files\Microsoft SQL Server\MSSQL\Binn’
The backup cannot be done for all databases at once and it must be done individually. This can be done by the line below and then just duplicate it for multiple databases.
Create a batch file and run the following:
CD "C:\Program Files\Microsoft SQL Server\MSSQL\Binn"
sqlmaint -D "MyDB" -BkUpDB "X:\Backups\Data" -Rpt "X:\Backups\Reports\MyDB.txt" -BkUpMedia DISK