Q: iOS 8.0.1

If using IE it saves the file as a zip file. Either rename the zip to ipsw, extract the ipsw file from the zip file or use Chrome or Firefox as your browser . Both of those will download as the ipsw file you need.

Follow the instructions in this support document. Loss of cellular service or ability to use Touch ID after updating to iOS 8.0.1 on iPhone 6 or iPhone 6 Plus

Chris only issue here is Apple seems to have left out of that KB the fact that IE for Windows users always downloads ispw files as zip. Chrome or FF does not do this. However you can simply rename the zip file and it will work.

To be honest, I would like to test that. Where do I go on the Apple site to download this iOS8 ispw file?

Forget that. I just realized the link was in the support document.

More than likely that is because the ispw file is not something that IE recognizes. Doesn't matter for me, since I do not have an iPhone 6. Sorry I interfered.

There is a link to it in the article you posted, Chris (step 4). But i can confirm, it does - at least in IE9 - download it as a zip file.

HT6487

No prob not interfering at all.  Apple just needs to add that info to the KB for Windows users otherwise a lot of folks are going to have the same issue trying to follow the KB step by step.