what about imac 27 inch mid2010
what about imac 27 inch mid2010? & imac 21.5inch mid 2011 Bootcamp for WIN10 64 Bit
iMac (21.5-inch Mid 2011), OS X El Capitan (10.11)
These are not supported for W10 by Apple. Please see Use Windows 10 on your Mac with Boot Camp - Apple Support . You will need to experiment, if you really want W10.