Take a look at this:
http://exceltip.com/exceltips.php?view=category&ID=20

Good info. there. Now, having dealt with this quite a bit in the part, I'd
say try to avoid it at all costs. Excel security is pretty weak; you can
prevent the casual user from pretty much anything, but you won't protect your
app. from an experienced user!! I have some code that will disable an app.
if it is removed from a network environment; I think I got the code from Jim
Thomlinson. This will add a level of security to your project, but again,
any advanced user can figure it out and disable it pretty darn quick. It
sounds like you developed an app. and now you are trying to sell it to end
users. If that's the case, the JT code won't help...

For time bomb info. look he
http://www.cpearson.com/excel/WorkbookTimeBomb.aspx


Hope that helps a bit.

Regards,
Ryan--

--
RyGuy


"NOPIK" wrote:

On Feb 14, 1:10 pm, phil wrote:
I am currently developing an Excel solution. I need to lock the excel
workbook so it can:-

You can encrypt everything with external library or hardware key
(dongle).
But, experienced user can always gain access to VBA code and worksheet
content. These two parts can't be effectively protected.