Backup Disc (DVD-RW) Write Protected?

I finally got around to deciding to create some backup/recovery discs for my new computer. Initially, I was going to do a "system restore" type of backup disc, created it, and then decided, alternatively, I was simply going to create a group of three discs, for in the event I feel like crashing/erasing my computer and want to put bare-minimum Windows 7 back on. When I attempted to erase the disc I had put the original back up on, it said it was write protected. I can't erase it manually (simply right clicking and deleting) I tried Nero, as well as numerous other burn/ripping programs that were mentioned to me.

Nothing works.

Any advice?

 

it's an r/w, should be able to erase it. however, if the program u used to burn the disc, closed the session, then the info is no longer rewriteable.