Need bootable no install SL 7 DVD

[Yasha Karant]

My spouse's laptop appears to be failing in hardware -- there are 
repeated errors coming from the SL 6 boot screen including what appears 
to be a failing hard drive (but this could also be the mother board disk 
controller).

As we cannot afford a linux certified laptop, and I plan to upgrade her 
to a machine that is provisioned for 64 bit operation, we will need to 
find a commodity laptop at a big box merchandiser (typically under 
$500).  However, all of these machines will have MS Win preinstalled.  
In the past, if we are considering the purchase of such a machine, I 
have inserted a bootable standalone with Xwindows and network SL DVD -- 
if all of the hardware is recognized (that is, drivers exist), we will 
consider the machine.  If the machine has proprietary MS Win hardware 
(drivers not part of the "stock" SL distribution), we look elsewhere.

Is SL-72-x86_64-2016-02-03-LiveDVDkde.iso 
<http://ftp1.scientificlinux.org/linux/scientific/7x/x86_64/iso/SL-72-x86_64-2016-02-03-LiveDVDkde.iso> 
the correct image to burn to a DVD to be able to perform the above test 
(bootable, runs, but does not install anything on the existing hard 
drive)?  I prefer KDE to Gnome 3, but could burn the gnome variant 
(SL-72-x86_64-2016-02-03-LiveDVDgnome.iso 
<http://ftp1.scientificlinux.org/linux/scientific/7x/x86_64/iso/SL-72-x86_64-2016-02-03-LiveDVDgnome.iso>). 
Will this test the WNIC as well as the video and audio cards in the 
machine?  Are there any predefined login/password accounts on the above 
ISO images, and if so, what account and password?  Typically, there were 
none.

Yasha Karant