Bootcamp software for MacBooks older than 2012
Download BootCamp and open command line as an Admin (cmd+x -> command line), cd to bootcamp install folder/BootCamp/Drivers/Apple/, run BootCamp.msi. It should skip the check for your MacBook compatibility.


P.S.: I installed BootCamp like this on my PC for compatibility with my apple keyboard. The normal install fails with message about compatibility.