What is the outlook for backwards compatability 10-20 years into the future? Right now I have a huge amount of articles, presentations, assignments, and excel spreadsheets stored on my computer. The information is frequently backed up to a portable hard drive. The primary file extensions are .xls, .doc, .pdf, .ppt, .bmp, .txt, .jpg, and .gif. I prefer the electronic format over paper since it is very easy to print, search, send, organize, modify, and transport. However, I am worried that I will not be able to access the files 5,10, or 20 years down the road (from different storage media, of course). Does anybody think this will be a problem?