USE master  
Go  
ALTER DATABASE model  
    MODIFY FILE ( NAME = 'modeldev' , FILENAME = E:\MSSQL\DATA\model.mdf' );
Go  
ALTER DATABASE model  
    MODIFY FILE ( NAME = 'modellog' , FILENAME = L:\MSSQL\DATA\modellog.ldf' );
Go  
ALTER DATABASE msdb  
    MODIFY FILE ( NAME = 'MSDBData' , FILENAME = 'E:\MSSQL\DATA\MSDBData.mdf' );
Go  
ALTER DATABASE msdb  
    MODIFY FILE ( NAME = 'MSDBLog' , FILENAME = 'L:\MSSQL\DATA\MSDBLog.ldf' );
Go  

See where your system dbs are located:

USE master  
Go  
SELECT  
    DB_NAME(database_id)  AS "Database Name"
  , name                  AS "Logical File Name"
  , physical_name         AS "Physical File Location"
  , state_desc            AS "State"
FROM  
    sys.master_files
WHERE  
    database_id IN (DB_ID(N'msdb'), DB_ID(N'model'), DB_ID(N'temp'))
ORDER BY  
    DB_NAME(database_id);
Go  

As this was a new server, with a new set of backup and disaster recovery procedures, I decided to do a full backup, and then completely truncate the transaction log.

Your Transaction Log could be crucially important in a recovery scenario, do not just do this because it's big and you want it to be small - it has a purpose.

MS SQL Server 2014 (2008/R2+):

ALTER DATABASE <DatabaseName> set recovery simple
GO
CHECKPOINT
GO
DBCC SHRINKFILE (<TransactionLog>,1)
GO
ALTER DATABASE <DatabaseName> set recovery full
GO   

MS SQL Server 2005:

USE <DatabaseName>
GO
DBCC SHRINKFILE (<TransactionLog>, 1)
BACKUP LOG <DatabaseName> WITH TRUNCATE_ONLY
DBCC SHRINKFILE(<TransactionLog>, 1)
GO

Query: Source
GUI: Source

1. Stop MSSQLSERVER and related services.

2. Open your DATA folder, or wherever the .LDf and .MDf files are stored (of the DB being restored).

3. Move the files to another folder

4. Restart SQLSERVER service (and related services).

5. Start my MS SQL Management Studio and delete the database in question.

6. Make sure the *.LDF and *.MDF files are gone from their original location folder.

7. A. Delete the database in question and attempt the restore from scratch; OR:
   B. Take the database Offline, copy the .LDF and .MDF files into the DATA directory (from Step 3).

8. Bring database Online.

Source Source