Truncate the log and Modify the user DB initial log file Size

DBCC LOGINFO

GO

USE DB

GO

BACKUP LOG DB TO DISK='F:\Backup\DB.trn'

GO

ALTER DATABASE DB SET RECOVERY SIMPLE ;

go

DBCC SHRINKFILE(DB_log,TRUNCATEONLY)

GO

ALTER DATABASE DB

MODIFY FILE

(NAME = DB_log,SIZE = 1024MB)

GO

DBCC LOGINFO

GO

ALTER DATABASE DB SET RECOVERY SIMPLE ;

go

DBCC SQLPERF(LOGSPACE);

GO