We've created this Forum Thread with some workarounds and advice to assist you in publishing you ebook.
MS Word 2007 Not Converting to PDF
When I try to save a DOCX file as a PDF it tells me that another user (who doesn't exist) or another program (which is not identified) has a lock on the file and it can't save it, though it will save as any other file type. Yes, I have installed the MS "SavePDF" extention though that had no effect. The MS help center's advise is no help.
Has anyone conquered this issue before? What's the trick? Fortunately, my machine at my workplace will do the conversions, but is inconvenient to use my employer's equipment for this. Help please?