Agree with Master Gail Or if you do not need the Logs Just drop the database and then attached the data files with no ldf file. That way a fresh ldf file is created and you will not have any log history.

USE [master]

GO

EXEC sp_attach_single_file_db @dbname='TestDb',

@physname=N'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\TestDb.mdf'

GO

OR

CREATE DATABASE TestDb ON

(FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\TestDb.mdf')

FOR ATTACH_REBUILD_LOG

GO