As a newbee, I inadvertently purchased (100!!) CD-R and would like to know how to format them to R/W so I can put text on them and add/change the contents. Thanks.

Short answer, you can't
CD R is CD R
CD RW is CD RW
Not the same
Not possible,
CD-R are Recordable ONLY media!
CD-RW are ReWritable media !
CD-Rs are considerably less expensive than the rewritables (at least) You can do a multi-session burn, but once you're done, that's it.
Life is hard; it's harder if you're stupid. -John Wayne
The CD-Rs are not a waste. Just adapt to a new way of backing up. Maybe, get a couple of CD-RWs. Use them for interum backups and then copy them to CD-Rs when they are full. With a little ingenuity, you can come up with a good plan.
As a favor to jangunder, I'll take those pesky CDRs off his hands for him. I will even contribute a little for postage. Not too much as I'm already doing him a big favor! Musky
If the voices inside my head paid rent, I'd be rich!
Every once in a while this place makes me smile. Now is one of those time. Thanks Musky.
