Converted PDF file not recognized

I am new to PDF Creator, need to convert Word documents to PDF. I downloaded the program and installed. It seems to work except:

Using PDF Creator, I converted a Word file, copied the resulting PDF file to a flash drive, and moved it to another computer. The newly created PDF file was not recognized. All other files on the flash drive appeared, only this one was missing. I could see it and open it on the original computer, but not the second. What could cause this?

Then I converted the same Word file again, this time using the Microsoft add in converter for Office 2007. I could find and read this file on either computer.

I checked the file properties of the two PDF files and found the files were much different in size: The one from Microsoft was 70 kbytes, the one from PDF Creator was 14 kbytes. Also the one from Microsoft was "tagged PDF", the one from PDF Creator was not tagged. I do not know what tagged means, but it was one of the properties in the file properties window. Any ideas?

Thanks for any help.