This really isn't on-topic, but people seem to want to talk about computer subjects on all the mailing lists. I don't know how long CD-R's or CD-RW's will last and no one really knows although there have been several accelerated aging tests done. Do some searching on the Internet. Most quotations that I have seen give anywhere from 50 years to well over 100 years for a CD-R. CD-RW's are considerably less reliable and really shouldn't be used for long term storage. They are fine for routine backups that probably won't be kept for more than a few years at most. The main point that most people never address is the fact that it really does not matter if they last 100 years. Do you really think the normal personal computer of 100 years in the future will be able to read a CD? By that time there will probably have been several generations of storage media in use. The future will probably belong to some form of crystalline or solid state storage. Not many people today have the ability to read media from just 15 or 20 years ago, like 8 inch or 5 1/4 inch diskettes or cassette tape storage. The point is that if you want to keep data alive and usable in the future, it will have to periodically be copied to new types of media. If that is not done because of time or money considerations, then the data will be unavailable even though the old media is still in good condition. The best media for preservation has always been acid-free paper. It can be read by anyone for hundreds of years in the future, but its storage costs are very high and accessibility is inconvenient. Microfilm has a good lifetime, but it can deteriorate with age and shows wear and scratches with usage. Master copies have to be kept under controlled conditions to periodically replace damaged films and to create copies for new distribution. This adds expense and inconvenient availability. Of course, neither paper or microfilm can be electronically searched. ======================================== Charles R. Weese, 4012 Pardee Rd., Stow, Ohio 44224 See http://web.raex.com/~cweese/weese/ and http://web.raex.com/~cweese/vance/ for my family info. I maintain the following USGenWeb county sites: Gallia County Ohio at http://www.rootsweb.com/~ohgallia/gallia.htm Jackson County Ohio at http://www.rootsweb.com/~ohjackso/jackson.htm Vinton County Ohio at http://www.rootsweb.com/~ohvinton/vinton.htm