For the C programming course I pulled out training material written fifteen years ago. It was quite good at the time, and I thought I'd just print it out quickly and give it to my students. Was I stumped, when Word 2003 wouldn't recognize the content of the documents? Not really, but I did utter the odd foul word or two. I couldn't remember in what version of Microsoft Word I'd written the documents, but I realized it must have been something like Word 3! A quick install of Word 6 allowed me to at least open the documents. Apart from the odd character which wasn't correctly recognized, they looked ok. I fixed those and saved them in Word 6 format, then opened those in OpenOffice and saved the lot as PDF(Portable Document Format). Will I be safe for a few years to come? I should think so. Never the less: one thing will always hold true: always keep valuable stuff in plain text.