Anyone like me who's held a full car license for several years should already know most of the answers to the questions that aren't bike specific, but where this product comes into its own is in helping you to become familiar with the format of the exam (it exactly matches the test you end up taking at the test centre) and getting a chance to brush up on the bike-related questions (bike safety, maintenance, specific rules of the road and the like).
If you practice on these questions, you will recognise them come up again *verbatim* in the real test - I found this useful because I remembered where I'd made a couple of daft mistakes at home when the same question came up in the test.
Contrary to what another review said, I had no issues with installing and running this software on Vista, though admittedly that review is several months older and the software may have been tweaked since then.