Mac OS X El Capitan BootCamp doesn't target Windows 10 ISO I was trying to install Windows 10 besides my Mac OS X El Capitan. 
I followed the normal steps I found on the Internet, but when I started to apply I got this and no idea what I should do in order to install Windows.

After I click continue, I choose which USB to save the downloaded file on, and then nothing changed; I still can't finish the process of pointing to an ISO image of Windows 10 that I want to install.



Note: my MacBook Pro is manufactured I think in 2010/2011.
It's a Core i5, 4GB RAM.

Windows 7 was installed on it besides my El Capitan OS X a month ago, and BootCamp was deleted by my son.
Unfortunately your particular Mac does not seem to support Windows 10. You can check the link here to verify. The last supported version of Windows on your Mac is 8.1.

Some people have had success installing 8.1 and then upgrading to 10, but you will not get Apple supported drivers and installation might be problematic. Unless you have particular reasons for needing Windows 10 you may want to stick with Windows 7.