Try:
WITH myTableWithRows AS (
SELECT (ROW_NUMBER() OVER (ORDER BY myTable.Salary DESC)) as row,*
FROM myTable)
SELECT * FROM myTableWithRows WHERE row = 3
Or:
SELECT *
FROM (
SELECT *, ROW_NUMBER() OVER (ORDER BY Salary DESC) AS RowNum
FROM [MyTable]
) AS MyDerivedTable
WHERE MyDerivedTable.RowNum = 3