While many official Apple download pages for older Boot Camp versions have been archived, you can still find the verified ZIP package on Apple's servers: Official Apple Download (BootCamp5.1.5621.zip) Compatibility
: 13-inch, 15-inch, and 17-inch models (Early 2011, Late 2011, Mid 2012); Retina models (Mid 2012, Late 2012, Early 2013). Mac Pro : Early 2009, Mid 2010, and Mid 2012 models. Mac mini : Mid 2011 and Late 2012 models. boot camp support software 515621 verified
, which is usually downloaded directly through the Boot Camp Assistant on macOS. Newer Macs While many official Apple download pages for older