How to convert Windows 8.1 .exe file to ISO image for installation via Boot Camp?

Needing the full hardware resources then is probably #1 and essential which a VM and running side by side won't, sharing RAM, processors. and the graphic card.

The nice part of a VM besides avoiding dual boot is also avoiding partitioning; the ability to locate Windows VM image anywhere, not just the boot drive or such (a Mac Pro can of course use all 4 internal or more hard drives), a Mac Book cannot.

If you want to use Mac OS X at the same time as Windows, run one of these:

VMWare Fusion

Parallels

Virtual Box (Open Source)

If you are willing to alternate Boot Windows -OR- Mac OS X, all you need is Bootcamp Assistant (and your Windows installer, of course.)

>>NB In any case, do not allow Windows to directly modify the Partition Map or change the size of any Partition. That will wipe out the Partition Map, and Mac OS X. Windows is not a pleasant guest.

If I may be allowed to muddy the water a bit here (👿), I run Bootcamp and VMware, both. If I need something intensive/or need hardware access (like updating firmware for devices which do not have a OSX firmware updater equivalent) I reboot into bootcamp, if I need something quick, I just fire up Vmware and run the Bootcamp as a VM machine. I do not create a separate virtual disk mapping the Bootcamp partition, because that to me is wasted disk space. 😉

Let us say that your Bootcamp is 64Gb, and your VMware virtual disk is 64Gb as well. In either case the disk space is allocated and used. You can look at the .vmdk file sizes (2Gb chunks or a single virtual disk). I am not certain you gain much.

However, the disadvantage of Bootcamp is that a single drive bootcamp installation disk cannot and must not be partitioned further.

Please pardon my ignorance on this subject.

But isn't 100GB the number we usually talk about for casual use of Windows?

And do you need that in both a physical partition AND a File? Can you BootCamp with just a file?

It depends on how much local data you want to keep on the Windows side. I have a 32Gb W8.1 installation, but there is very little non-OS information on the C: drive. You can make it larger. I also have a 256Gb partition for Bootcamp (on a different machine) which is a much more independent installation where I can locally store documents. This one is also used under VMware.

VMware will boot a Windows installation on the Bootcamp partition without a reboot normally required if there was no Vmware layer. It does not require a virtual disk, it will use the Bootcamp filesystem.

Bootcamp requires a partition, but VMware can be used (without Bootcamp being installed) using a virtual disk. One additional advantage of VMware (and other VM solutions) is the ability to expand the virtual disk based on available underlying physical drive space. It is a bit of work to expand a VMware installation virtual disk, but it is possible.

In contrast, Bootcamp partition expansion is an order of magnitude more painful and requires re-installation of Windows (Winclone has a workaround). There are other challenges with Bootcamp due to the implementation that Apple engineers chose (words like EFI/UEFI and CSM-BIOS come into play on this subject).

A virtual disk appears as file(s) to OSX and can be backed up via Time Machine, but a Bootcamp partition cannot be backed-up/restored via Time Machine. There is no way to partially restore a part of the virtual disk either.

So either choice, on it's own merit has drawbacks, but combined with each other can, they can address some of each others limitations. OSX can read an NTFS partition, but requires third party assistance to write. VMware allows file sharing between the two OSes.

This is a high-level set of differences in either approach. You can spend some time on the Apple Bootcamp page for further reading, while VMware ha a huge documentation library/KB at your disposal.

The .exe file can only be executed on a Windows machine. What is the name of the downloaded file? If it creates a directory structure, you can burn the directory structure and its contest to an ISO.

How large is the file?

You may just have the downloader.

then you have a setup installer that pulls down the full installer.

Have you considered instead of running Windows natively (Boot Camp) to run it in a VM (Parallels etc) under OS X instead?

VirtualBox is free while Parallels and WMWare Fusion are paid.

My experience is that Parallels is more responsive that VirtualBox