WesternDigital DLG117(Data Lifeguard Diagnostic) not for win7?

I have some lag issue with my pc and would like to check izit my Harddisk corrupted or with any bad sector.

I'm using 500 GB Caviar Blue WD5000AAKS, i try to install the program DLG_117 and its able to run with my x86 Win 7 Home Premium.

The application runs smoothly but in the menu, it can't detect my Harddisk!
there are 2 collum, Physical Drive & Logical Drive.
In logical drive, it able shows my Drive, total space & free space.
but for Physical Drive, it state "there is no item show in this view "

This application is usable for all OS but it never write Win 7 in the list.

So, any help on this or is there any other way to diagnos my Harddisk?
many thanks....

 

thanks for the advise Pete, will give it a shot later.