Change tracking SQL Server 2008
If you can't add any extra storage for the data (as noted in your comment) then you simply can't do this.  SQL Server doesn't track the old and modified rows for you.

There's a duct-tape way of doing it temporarily: you can read the transaction log.  When combined with the full chain of backups, you can build the old &amp; new data together.  Third party data recovery products like Quest LiteSpeed do this - for any transaction, they'll show you the old and new data by reading through the full backup and transaction log backups.