Solved Windows 7 ISO files from dvd and MS online

May 12, 2020 at 00:06:22
Specs: Windows 7, Pentium D
Is there a difference between a Windows 7 ISO file created from installation dvd and the ISO file downloaded from Microsoft?

message edited by Peter0188


See More: Windows 7 ISO files from dvd and MS online

Reply ↓  Report •

✔ Best Answer
May 13, 2020 at 06:59:04
The required boot system (think of a min dos installation) is added to a DVD when the ISO is burned. It isn't part an ISO itself. i.e. there is no bootable .exe file or equivalent included in the ISO itself.

When you "burn" - NOT copy - the ISO to bootable media (CD/DVD/usb memory stick) that is when that bootable media (.exe) is added into the equation; and that is how the bootable medium (containing the ISO) boots.

These links may also be of interest, as they discuss installing from an ISO (within a booted/working operating system:

https://uk.pcmag.com/gallery/121980...

https://www.raymond.cc/blog/how-to-...

But if there isn't a properly booted/ fully working system then one has to burn the ISO to bootable media and boot up with that...



#1
May 12, 2020 at 00:16:20
We can't know, you need to install the the one you created & test.

If you are doing a clean install, boot from it & during the install. Delete all the partitions.

Keep hitting Delete until Delete & Format are greyed out & you are left with an Unallocated drive.

Proceed.

No other drives should be connected during the install.

message edited by Johnw


Reply ↓  Report •

#2
May 12, 2020 at 00:36:35
I should have also asked, what makes the downloaded ISO bootable?
Is there a "boot" or exe file of some sort within the ISO?

Reply ↓  Report •

#3
May 12, 2020 at 00:40:31
"I should have also asked, what makes the downloaded ISO bootable?"
Right click on the ISO & select burn.

Do you know how to proceed after that?


Reply ↓  Report •

Related Solutions

#4
May 12, 2020 at 04:47:50
The ISO file needs to be properly burned (not simply copied) to a DVD or USB flash drive. Try either ImgBurn or CDBurnerXP, both are free. And to install from either media, you'll have to make sure the boot order in the BIOS of your device is configured correctly.
https://cdburnerxp.se/en/home
https://www.imgburn.com/

If you have a Win7 product key, why not use it to install Win10 instead?
https://www.microsoft.com/en-us/sof...


Reply ↓  Report •

#5
May 12, 2020 at 04:48:15
Johnw,

I wonder if you understood Peter's last question.

I have never created or used an ISO file/disk, and
have the same question about them: What runs the
ISO file? Is there a startup operating system similar
to DOS io.sys and msdos.sys in the ISO that runs
when you boot the disk?

In other words, "What makes the ISO bootable?"

-- Jeff, in Minneapolis


Reply ↓  Report •

#6
May 12, 2020 at 04:53:46
"What makes the ISO bootable?"

Jeff

Just right clicking on the ISO & clicking on burn, makes a bootable DVD.

What code it adds, I have no idea, never needed to know that.

message edited by Johnw


Reply ↓  Report •

#7
May 12, 2020 at 05:09:47
Thought I'd better fire up a W7 comp, right clicking on the ISO doesn't apply, must have started with W10.

riider has provided the tools needed.

Another choice is to use this tool on a thumb/usb drive.

Rufus
https://www.softpedia.com/get/Syste...
http://www.freewarefiles.com/Rufus_...
http://www.freewarefiles.com/screen...
http://rufus.akeo.ie/


Reply ↓  Report •

#8
May 12, 2020 at 05:14:41
"What makes the ISO bootable?"

This particular ISO is an exact copy of a Windows disc, so what would make the Windows disc bootable? Bootmgr or Bootmgr.efi?
https://uefi.org/sites/default/file...


Reply ↓  Report •

#9
May 12, 2020 at 06:00:11
Thank you.

So dumbed-down, yet so far over my head.

-- Jeff, in Minneapolis


Reply ↓  Report •

#10
May 12, 2020 at 07:15:14
If you want to learn more about this then i recommend downloading MDT. With MDT you can create a custom Install Media that you can deploy from servers with WDS or from a USB.

https://docs.microsoft.com/en-us/wi...


Reply ↓  Report •

#11
May 12, 2020 at 08:19:54
That's a very complex discussion etc. on the MS link in #10... but I don't see it answers the question "what makes an ISO burned to a DVD bootable?"

As I understand it... an ISO is essentially zip file, likely even a self extracting zip file - which requires a minimal dos based routine to run it? .

So perhaps when this is burned to a DVD (or CD if a CD is big enuff) it includes a wee dos style boot routine (courtesy of the windows OS in this case; presumably similarly with Mac/Linux systems too) which is enabled when the system boots from the DVD/CD (selected as boot device) and the that dos routine then triggers the self extraction of the "zip" folders/files...?

Pure theory/speculation on my part... and I'm happy - open - to be corrected and have the actual how it does work - clearly explained...


Reply ↓  Report •

#12
May 12, 2020 at 08:27:51
The first part of this how seems to support my theory/explanation to some extent; as it refers to a minimal OS (a set bootable set of files) which is added to the DVD - not the ISO itself - and which boots/runs the system initially; thus allowing the DVD to come into
play as there will be CD/DVD driver included in that minimal OS?

https://dvdcreator.wondershare.com/...

and this in its own way covers the same ground...?

https://www.passmoz.com/make-bootab...


Reply ↓  Report •

#13
May 13, 2020 at 06:10:29
To un-confuse you all, the purpose of the question is to clean-install Windows 7 using usb.

I have 2 options:
1 - copy an iso created from Windows 7 dvd to usb and install with that
or
2 - download iso onto usb and install with that.

But tvlr@8.19 might have explained it all. Upon booting, the iso file self-extracts just like a zip file and installation carries on from there. So it doesnt matter if the iso is from dvd or download as they should be equally the same. And that theres no special "boot" or exe file included with the downloaded iso.

Am I right?


Reply ↓  Report •

#14
May 13, 2020 at 06:59:04
✔ Best Answer
The required boot system (think of a min dos installation) is added to a DVD when the ISO is burned. It isn't part an ISO itself. i.e. there is no bootable .exe file or equivalent included in the ISO itself.

When you "burn" - NOT copy - the ISO to bootable media (CD/DVD/usb memory stick) that is when that bootable media (.exe) is added into the equation; and that is how the bootable medium (containing the ISO) boots.

These links may also be of interest, as they discuss installing from an ISO (within a booted/working operating system:

https://uk.pcmag.com/gallery/121980...

https://www.raymond.cc/blog/how-to-...

But if there isn't a properly booted/ fully working system then one has to burn the ISO to bootable media and boot up with that...


Reply ↓  Report •

#15
May 13, 2020 at 07:43:22
If you want to create a bootable usb drive, then i suggest you download microsofts media creation tool and use that to write the iso file to the usb.

As mentioned above you cant just copy the iso file.
The media creation tool is easy to use, but if you get stuck theres a lot of guides and how-to's you can follow.

message edited by Kilavila


Reply ↓  Report •

#16
May 13, 2020 at 21:12:44
I get it now. The iso has to be burnt rather than copied.

But that brings me to another question: where does the bootable media come from or how is it added?


Reply ↓  Report •

#17
May 14, 2020 at 01:36:29
The utility - be it part of the OS booted or a separate item - used to burn the ISO provides that necessary bootable part. Logically it’s a file type and format common to all (current) OS?

Reply ↓  Report •

#18
May 15, 2020 at 22:25:46
Ok I got it all now. Thank you all for responding.

Reply ↓  Report •

Ask Question