Set all databases to the recovery model of your choice. Replace <RECOVERYMODEL> with Simple or Full.

USE master
GO

-- Declare a variable to store the value [database name] returned by FETCH.
DECLARE @dbname sysname, @cmd varchar(1000)

-- Declare a cursor to iterate through the list of databases

DECLARE db_recovery_cursor CURSOR FOR
SELECT name from sysdatabases

-- Open the cursor
OPEN db_recovery_cursor

-- Perform the first fetch and store the value in a variable.
FETCH NEXT FROM db_recovery_cursor INTO @dbname

-- loop through cursor until no more records fetched
WHILE @@FETCH_STATUS = 0
BEGIN
IF (SELECT DATABASEPROPERTYEX(@dbname,'RECOVERY')) <> '<RECOVERYMODEL>' and @dbName <> 'tempdb' BEGIN

-- create the alter database command for each database
SET @cmd = 'ALTER DATABASE "' + @dbname + '" SET RECOVERY <RECOVERYMODEL>'

-- alter each dataabase setting the recovery model to <RECOVERYMODEL>

EXEC(@cmd)
PRINT @dbname
END

FETCH NEXT FROM db_recovery_cursor INTO @dbname
END

-- close the cursor and deallocate memory used by cursor
CLOSE db_recovery_cursor
DEALLOCATE db_recovery_cursor