I don't pretend to understand but from what I have read just now there seems to be some requirement for a printer when attempting to convert spreadsheets to PDF files.
What I read offers a utility called novaPDF which is "installed as a virtual printer so you can create PDF files simply by printing to it instead of your normal printer".
It's a workaround, so may not be ideal, but if you want to try it, the full article is here;
I hope that helps.
I am running Office 2007 on WinXP SP3. I downloaded the "Save as PDF" plugin, which I use all the time to convert Word documents to PDF files. Today I tried it with an Excel spreadsheet, but got the message that "No printers are installed" followed by "The document was not saved." I installed the text only printer driver and now get the message that "The printer is unavailable" followed by "The document was not saved."
What is going on here? Why are printers entering the equation at all? I don't think I should have to install a separate PDF printer, but knowing Microsoft it may come to that.