I bought a laptop that was return to store. The other guy made the famous recovery backup on 2 DVDs. But at least he pack them with the laptop.

Since the manufacturer doesn't allow me to make a second backup of the recovery partition, I wish now to make a copy of the 2 DVDs on a single double layer DVD. Not only it will be more handy to have this on one disc I will get a second copy of the recovery disc in case the other get damgage.

Before you ask, the amount of data on the 2 DVDs can fit on the DL DVD (first DVD is full and the second is only filled at 1/4 of its full capacity).
Also I found on internet the trick to download the program called "resetrmc.exe" a software that can be downloaded from Gateway website and used to reset the "flag" that tell the laptop that the recovery disc was made once. BUT IT DON'T WORK AT ALL. HP probably find a way around that trick, but it sure don't work in my case... GeeWizz

All in all I want to know how to make a copy of two DVDs on a single double layer DVD using NERO 6 ? ... because it is not clear at all based on the options offered...

First off is the burner a DL or SL burner?? Also have you tried to recover the laptop with the DVDs to see if you can bypass the laptop into thinking it's the first time it is doing a recover DVD? Also Gateway and HP aren't the same company....maybe if you contact HP that would help more...but since I don't know what laptop you have I can't offer much more advice....?

Well, firt thing first:
Laptop is HP Pavillion DV6565CA. With a multi-DVD burner that can read and burn double layer DVDs. However I am using my desktop for "fusing" the 2 SL into one DL. This desktop has a DVD-ROM (reader) and a LG multi-DVD burner that can write DL DVDs. On the desktop I have NERO 6. I check the content of the two SL DVDs that contains the recovery partition. Their is various files and folders on each one and many are commons. The recovery software spreaded some files over the two SL discs...
DVD1: BASE1.VIM... 2,3,5,6 and 8
DVD2: BASE4.VIM... 7 and 9

Also I found the "SPLIT.LOG" file on each DVD in same directory has the *.VIM files.
content of SPLIT.LOG for DVD 1:

base.wim=0
base8.wim=0
base6.wim=0
base2.wim=0
base5.wim=0
base3.wim=0
base7.wim=1
base4.wim=1
base9.wim=1

Actually I refer to DVD1 and DVD2 but the recovery software use "0" for DVD1 and "1" for DVD2.
Now you will tell me that should be very simple to edit this SPLIT.LOG file to put "0" everywhere. However their is a master file that contains other informations and other files also and beleive me it is not clear to me that it will work. I may have to do some tests. However the only way to test it is to go to the lenghty process of reinstalling the complete system from disc. Lots of time and their is no guarantee that it will work.

Now, when you say: "Also have you tried to recover the laptop with the DVDs to see if you can bypass the laptop into thinking it's the first time it is doing a recover DVD?"

... I don't get it! What do you mean by that?
I do reinstall the laptop with the two SL DVDs. It reinstall the complete system with the recovery partition. Except if I try to make a recovery disc using the DL DVD, the recovery manager tell me that the discs were already done.
I think I will need to go in lots of time and trouble to get the recovery discs on one DL DVD... Maybe I am too picky... I have the discs made by the previous owner and they work!

But the question is raised and I see it as a challenge! But maybe someone picky as me went to the same process and succeed...

Any ideas?

First, browse doom9.org & videohelp.com!
There are many guides you can follow.

Easier to get a double disc box if you already have working discs and if you want to play the safe game backup them.