DVD-RW to DVD-RW

[mtdg]

I want to take DVD-RW discs I have recorder on my own set top box, take off the programs I have not watched form multiple discs and burn them back to another DVD-RW to watch on my set top box thus freeing up the other DVD-RW to be used again.

How?

I would hope that since there is no change in format I would be able to copy the program as 'data' without any convertion to / from another format.

[jman98]

This is possible, but it's not going to be easy. You'll have to rip the individual episodes and re-author. Your idea of simply doing some kind of data copy will not work.

I know you UK guys have a reputation for being, ahem, "thrifty" (I am being nice and not saying the word you so richly deserve to be called), but damn dude, just buy some more DVD-RW discs. They aren't that expensive. Look here:
http://www.discworlduk.co.uk/Blank-DVD-RW-p-1-c-506.html
You can get a tub of 10 Verbatim (best quality of all they sell) DVD-RW discs for less than 6 pounds including VAT. Of course if your time is absolutely worthless and you'd rather spend hours making new discs than just buying some extra DVD-RW discs, then I told you earlier what you have to do.
You could also consider just erasing the discs you have and not watching the shows you haven't seen. Seriously. If you haven't seen them yet, maybe they really just aren't that important to you.

[usually_quiet]

jman98 is right. What you want to do will probably involve more work than you want to put into it. I once created a DVD-RW with a very simple menu so a family member could watch several missed episodes of a favorite show that I had recorded. It took me something like 2 hours, but I had experience using these programs and authoring DVD's, plus the tools I used were already installed and working on my computer. In case you still want to go ahead with this project, I'll outline what I did using only free software:

1.) Finalized all the discs with the episodes to be saved.

2.) Used Rejig to demultiplex the audio and video for each episode and transfer them to HDD.

3.) Used DVDAuthorgui create a simple menu with a button for each episode, imported the files for the episodes, then authored the DVD. Guide here: http://download.videohelp.com/liquid217/dvdauthorgui.pl?p=guide1

4.) Tested to make sure everything was working.

5.) Burned to DVD-RW using ImgBurn.

Using the free trial of TMPGEnc DVD Author at step 3 instead of DVDAuthorgui may remove the need for step 2. There are undoubtedly other ways of doing this too, using other free tools, but I doubt that any will be as easy as you want them to be.