Hi

I would like to setup a macro within Excel that checks
which computer is using a particular Excel Doc.

I know of the Excel VBA command: Application.UserName and
the more complex VB codes to recall the NT network name
and computer name.
However these could be changed relatively easily for stand
alone computers.

Is there a command that gets the computer's "Hard Disc
Serial Number" or any other unique reference number that
identifies the particular computer ?

I use Excel 2003, and I am trying to find a way of
limiting the use of a particular Excel Doc to certain
users.

Many thanks for your input and comments

David Hall