can i install Windows 8.1 on a 27 inch, iMac late 2009 model? Is this supported by Apple?

Hello, before i start this endeavour is it supported by Apple to install Windows 81. on a late 2009 iMac 27 inch model? I get confused by all posts out there including on Apple's website. I'm happy to try it out but want to be sure that if i create a second partition for windows, my primary partion with MAC-OS does not get impacted in any way.

Thanks,

Martijn