SELECT h.* 
   FROM tHistoryLog h
  WHERE h.EventID IN (SELECT TOP 5 w.EventID
                        FROM tHistoryLog w 
                       WHERE w.EventID       = h.EventID 
                         AND w.ApplicationID = h.ApplicationID
                         AND w.TechnologyID  = h.TechnologyID
                         AND w.MachineName   = h.MachineName
                       ORDER BY w.CreateDate DESC)

-- stage the history log
CREATE TABLE	#Stage
		(
			RowID INT IDENTITY PRIMARY KEY,
			EventID INT,
			ApplicationID INT,
			TechnologyID INT,
			MachineName VARCHAR(20),
			CreateDate DATETIME
		)

-- copy the data in the wanted order
INSERT		#Stage
		(
			EventID,
			ApplicationID,
			TechnologyID,
			MachineName,
			CreateDate
		)
SELECT		EventID,
		ApplicationID,
		TechnologyID,
		MachineName,
		CreateDate
FROM		tHistoryLog
ORDER BY	EventID,
		ApplicationID,
		TechnologyID,
		MachineName,
		CreateDate DESC

-- create a temporary table for each group
CREATE TABLE	#Temp
		(
			MinRowID INT,
			MaxRowID INT
		)

-- select each group range
INSERT		#Temp
		(
			MinRowID,
			MaxRowID
		)
SELECT		MIN(RowID) AS MinRowID,
		4 + MIN(RowID) AS MaxRowID
FROM		#Stage
GROUP BY	EventID,
		ApplicationID,
		TechnologyID,
		MachineName

-- show the groups of data
SELECT		s.EventID,
		s.ApplicationID,
		s.TechnologyID,
		s.MachineName,
		s.CreateDate
FROM		#Stage AS s
INNER JOIN	#Temp AS t ON t.MinRowID <= s.RowID AND t.MaxRowID >= s.RowID
ORDER BY	s.RowID

-- clean up temporary tables
DROP TABLE	#Temp
DROP TABLE	#Stage