Gibson Research (GRC)'s SpinRite (http://www.grc.com/spinrite.htm) is the only program that I know and would recommend, that I know can do NON-destructive full-disk read-write testing. It has several limitations, including its US$90 price, but Steve Gibson "wrote the book" on HDD testing and it shows. FYI, if you think $90 is too much money, consider that Steve (the author) only writes in one programming language - x86 assembly!
Just don't mention SpinRite around Mr. Donovan. *wink*
-Montana