Updating boot camp mac
If you don't, you might see the message "press any key" or your Mac might not start up from Windows during installation.Some versions of Windows require a certain processor and more hard drive space and memory (RAM) than others.Check the documentation that came with your copy of Windows to find out what you need.Then use System Information to see what your Mac currently has.
You don't have to do a single thing if you're using Boot Camp to install a fresh version of Windows 10 on your Mac.
By default, Mac will always boot from the last-used startup disk.
If your copy of Windows came as an installation DVD, you need to create an ISO image from this media to install Windows using Boot Camp.
Before you upgrade, you'll first want to make sure that the Mac you're using actually supports Windows 10 x64 to begin with.
(Apple provides a helpful list for that.) Assuming it does, you'll want to boot into OS X and make sure that you have any and all software updates installed.
Switch over to your Boot Camp installation of Windows, and open the Apple Software Update tool.