If your Mac already have an existing Windows partition and the Mac are belong to one of the supported Mac to run Boot Camp 6.1.
To Upgrade Existing Windows to Windows 10 with Boot Camp The only difference is that you need to make sure to download and create a bootable Windows 10 USB from Windows 10 ISO. You can follow the same steps as we have guided you with install Windows 8.1 on Mac with Boot Camp. The steps to install a fresh Windows on your Mac is pretty much the same as any previous supported Boot Camp Windows versions. With this latest version of Boot Camp 6.1, Apple has dropped support for Windows in 32 bit, so if you have any Windows in running Boot Camp that are 32 bit, you will need to remove the partition and reinstall your Windows 10 in 64 bit. You get to experience all the goodies Windows 10 has to offer without the worry of any hardware that may or may not work. This means that you can now install Windows 10 to fully replace Mac OS X. Today, Apple released the latest Boot Camp 6.1 that supports a various range of Mac to run Windows 10 natively without a virtual machine enabler, such as Parallels. It doesn’t take Apple long to release all the drivers to support Windows 10 running natively on Mac.
