For PC’s older than 5 years, there is Xubuntu:  http://xubuntu.org/

For newer PC’s there is Ubuntu:  http://www.ubuntu.com/

For professional media users, there is Ubuntu Studio:  http://ubuntustudio.org/

Your computer will run faster, much faster!

Ubuntu does everything Windows does, and OSX, and yes it installs on Mac hardware too, I know because Im running Ubuntu 14.0.4 on a 27″ iMac.  There is a wealth of FREE software too, check it out