>>>Does anyone know of a product that can read a data file and advise the format?
>>
>>I haven't used it, but others have used this product in similar situations (used to be called DataJunction): http://www.pervasive.com/dataintegrator/index.asp
>>
>>>
>>>I have a potential client that has data locked up in an existing system, and I only get the sale if I can read his existing data.
>>
>>Are you sure it's legal to do so? A far better option is to get help from the company that created their current system.
>
>As far as I know, the data always belongs to the client, not the system creators, even if the data is encrypted or "hidden" in some way.

Maybe you haven't yet encountered the situation where the ownership of the computers in question - or the software - or even the entire company is in dispute between battling partners/shareholders. Quite often one party will try to do an "end run" around the others by trying to get customer lists, accounting info etc. to which they are not entitled. These types of situations are very ugly to get involved with as 3rd parties.

There are lots of other potential legal minefields you can inadvertently walk into. In the situation outlined in this thread I wouldn't dream of undertaking the work unless I could contact the developer of the current system, or the company provided a darn good reason (which I would verify) why not (e.g. developer died, joined a monastery etc.)