pdf files didn't work at all on our laptop (windows 7)...though the computer tried (unsuccessfully) to load an updated version of Adobe reader

Some of the pdf files worked on Windows 8, some had "property of Marlow..." on them

(geez....'puters are a PITA...sigh.... )

and just to prove that point, the CB spellchecker insisted that "'puters" should be spelled putters...!!