PDF from Mac does not open at Windows...!!!

Can you tell us what options you used to create the PDF? i.e. export from Numbers, or PDF from the print dialogue?

You may want to look at exporting the file from Numbers as a PDF or Excel...it's possible that the file being attached has not been reformatted and the recipients are opening a file still formatted to be read in numbers only. See http://support.apple.com/kb/HT3719...hope this helps : )

If you have the file, and can manually have it set to open using
Adobe Reader instead of the default Apple Preview (or the app
which created the file, which the recipient does not have) then
perhaps someone using windows can open it in their Reader.

However, I am not sure if you can select a default choice an-
other operating system could use, such as you can with the
Mac OS X; since you can choose what to open a file with,
but may not be able to have that choice stick for the recipient.

Hard to say, but sometimes that kind of thing works.
Of course, if the recipient has a GMail account the
.PDF may work in there, no Reader or not.

In any event...
Good luck & happy computing! 🙂

I use "export" from numbers-->PDF,

Does it work to create your pdf using the pdf button in the print dialog?

Frequently a PDF exported from an iWork app defaults to have the extension hidden, and when attached, I do not see the extension -- at least while composing. I always make sure to deselect to have the extension hidden using Get Info or other access, and I have never tempted fate to leave it hidden before attachment.

Just a thought, but perhaps worth checking, since Windows requires the extension to know the file type.

Ernie

I am saying that might be a problem -- have never tested sending the message with the extension hidden. Presumedly if Always Send Windows Friendly is selected (as would be advisable, also), the extension may get revealed, but again I have not tested.

When attaching, you can briefly select the More Info button, and do the same in that resulting info dialogue.

Ernie

Not sure what the PDF exported as PDF is not opening, however, am more familiar with exporting from Pages than from Numbers. It would be interesting to know if the PC is able to open other PDF files or not and with what application, ie Adobe. Apple technical support does have a department called iApps that specializes in Pages/Numbers/Keynote as well as all the iLife software. If you have applecare coverage, it might be worth your time to call Apple. If you don't have Applecare, there is a billable option for support. However, please keep in mind that it is hard to fix an issue on the receipients end if everything you are doing is correct on the mac end.