If you talk about the 2007 add-in see the code on this page
http://www.rondebruin.nl/pdf.htm

you can test it like this

'Test If the Microsoft Add-in is installed
If Dir(Environ("commonprogramfiles") & "\Microsoft Shared\OFFICE" _
& Format(Val(Application.Version), "00") & "\EXP_PDF.DLL") < "" Then


--

Regards Ron de Bruin
http://www.rondebruin.nl/tips.htm


"Basil" wrote in message ...
Hi,

I want to add a button on a sheet that will print sheets 5-9 to a pdf file.
I'm gonna have a play to try and work this out myself (I'm even gonna try and
get it to calculate page numbers and create a contents page within the
workbook! - any tips appreciated!!).

Starting question I have that I certainly need help with is this:
Is there some code I can write to identify whether or not the user has pdf
writer installed on their machine?

I want to disable the button on sheet activation if they don't have the
appropriate software.

Thanks! Basil