There will be no ISO downloads of Windows 8.1 for the public.

You can follow the workaround here:

http://philipyip.wordpress.com/download-microsoft-windows/download-windows-8-1-iso/ 

At current this is the only genuine solution available... although Microsoft should not be making Windows installation difficult.

I Have three computers at home. I enjoy windows 7 which came with the iso files. I would also enjoy the iso cd that comes with windows 8. I want the ISO cd, so that when my kids mess up the computers beyond repair I can fix the computer with the software I PAID FOR!!! Maybe I don't want to have an internet connection to use a PERSONAL COMPUTER!! Did you guys think of that? Seriously. I and We, should not have to have an internet connection to use our Personal computers. Not to install, nor to enable. That is what a code is for. Design a better code if the current one is failing.

Its still a very inefficient solution and not just due to wasted bandwidth.

Its much faster and the system is more reliable when Windows and its latest service packs are installed together... I am the author of Unofficial Dell Windows Reinstallation Guide and Related Wikies. The blog has 100,000 views and people that have followed my instructions have all reported significant performance boosts in comparison to factory settings.

Microsoft have the setup files so why aren't they letting Windows 8 OEM and/or retail users download a .iso directly.

Its not only that, there are multiple other issues such as the lack of ability to select between 32 and 64 bit. For instance if my Desktop died and had 64 bit Windows 8.1. My laptop is older and can only install the 32 Bit version. Saying my hard disc crashes on my desktop and I want to repair/replace it. Say I don't have media (I do but pretend I don't for arguments sake). Then I have to use the 32 bit laptop to download a Windows 7 64 Bit .iso (because its available) and create media and clean install and install the drivers to have the ability to access the internet. I then have to download the Windows 8.0 and then download and install all Windows 8.0 updates and then download Windows 8.1 and all its updates. 

Therefore you have time to not only download and clean install Windows 8.1 but also 8.0 and 7 also. Most users will have at least a Windows.old installation (which is wasted hard disc space) and unnecessary registry entries. My workaround still requires installation of 7 and 8.1 but omits 8.0 and all its updates.

Now what is a Service Pack - traditionally it is an accumulation of updates and why does it exist; to make deployment of the OS easier and cleaner aswell as increase performance and perhaps give so additional features. Releasing a service pack without a means to clean install it is absolutely ridiculous.

My solution is a valid workaround for retail media but there still needs to be a workaround for OEM media. OEMs never install Windows in a way that it is clean. Preinstalled junk and drivers may interfere with Service Pack updates and I have seen it happen countless times.  Unfortunately Microsoft seems to have OEMs arms tied and they cannot provide downloadable media to the customers. Customers are still being bounced between both parties for media requests particularly for the Service Pack update. Moreover Microsoft provide download links to Microsoft Office OEM but not Microsoft Windows OEM.

As mentioned installation and setup requires a Microsoft Account. The system is activated using the Microsoft Account, they even ask for the phone number. The least Microsoft could do is provide a link to a .iso installation file via email. It would solve a lot of problems.

Ironically regarding installation and setup; the pre-releases e.g. developer preview 8.0 and 8.1 aswell as consumer preview 8.0 and 8.1 and enterprize trial 8.0 and 8.1 have a much better service than the sold OEM/retail releases of Windows 8.0/8.1 as they all had a .iso download link. Customers paying Microsoft for something get worse service.

The only option I can suggest for those with download limits is to check to see if there is an off peak download time where you are not limit, some providers offer this from around 10pm to 7pm. I always do my heavy downloading just before I go to bed to avoid bandwidth throttling, it is also generally quicker during this time.

I think but I'm not sure that Belarc Advisor will tell you your key. Its a free download. There a probably other programs out there that will do the same thing.