The case statement seems to be correct, check the other sections of the code..
SELECT
Customers.CustomerID,
Customers.OldCustomerID,
LastName+','+FirstName+' '+MiddleName AS [Customer Name],
Left(FirstName,1)+Left(MiddleName,1)+LastName AS UserName,
zlu_Cars.Description AS Car,
zlu_CarColor.Description AS [Car Color],
zlu_Computers.Description AS Computer,
CASE IsLaptop WHEN '1' THEN 'Yes' WHEN '0' THEN 'No' END AS Laptop,
zlu_Race.Description AS Race,
zlu_Residence.Description AS Residence,
zlu_BirthMonth.Description AS [Birth Month]
FROM (((((Customers INNER JOIN zlu_Cars ON Customers.CarID = zlu_Cars.CarID) INNER JOIN zlu_CarColor ON Customers.CarColorID = zlu_CarColor.CarColorID) INNER JOIN zlu_Computers ON Customers.ComputerID = zlu_Computers.ComputerID) INNER JOIN zlu_Race ON Customers.RaceID = zlu_Race.RaceID) INNER JOIN zlu_Residence ON Customers.ResidenceID = zlu_Residence.ResidenceID) INNER JOIN zlu_BirthMonth ON Customers.BirthMonthID = zlu_BirthMonth.BirthMonthID
WHERE (((Customers.CustomerID)>499 And (Customers.CustomerID)<601))
ORDER BY Customers.LastName, Customers.FirstName;
SELECT Name, Rating,
CASE Rating
WHEN 'V' THEN 'Very Good'
WHEN 'X' THEN 'Poor'
ELSE 'Average'
END AS myratings
FROM table_name;