Data LifeGuard’s warranty column indicates whether a particular attribute will qualify your drive for replacement if its value falls below the threshold. Such attributes, eg Re-allocated Sector count, are considered critical. Other attributes, such as Start/Stop Count, would reflect wear-and-tear and would therefore not be warranty-able.
That said, you will get a more detailed view of your SMART data with either of the following utilities:
HD Sentinel (DOS / Windows / Linux):
http://www.hdsentinel.com/
HDDScan for Windows:
http://hddscan.com/
Look for reallocated, pending, or uncorrectable sectors.
See this article for SMART info:
http://en.wikipedia.org/wiki/S.M.A.R.T.
