How do I install windows 8.1 on an early IMAC, running os 10.9.1, with Boot camp 5.1.0 (473). Plan to use a hard connection for mouse and Keyboard, No camera either.
iMac, OS Ver 10.9.1
Windows 8.1 is not yet officially supported.
You could try it with Bootcamp Assistant and see how it goes, though it's possible you could have driver issues once installed.
The article Boot Camp: System requirements for Microsoft Windows operating systems
makes it look like the iMac Early 2009 only supports up to Boot Camp 4 and Windows 7 32-bit.
There are new versions of Boot Camp 5.1 that support Windows 8.1 but your iMac isn't listed there either. Boot Camp Support Software 5.1.5621
(click on System Requirements at the bottom to see the list).
WIndows 8.1
