1) Find your mysql path , Example "C:\Program Files\mysql\bin".
2) Open a cmd (command prompt)
--------------We will go to mysql path with cd and login to mysql
3) cd C:\Program Files\mysql\bin
4) mysql -u root -p mysql (It will ask you for your mysql password, right it and click ok)
--------------We are logged in now. ('root' is the username , 'yourpass' is your password for the remote connection, '%' is the basic part that allows all kind of remote connections. If for example you will set 192.168.1.150 , only machine with that ip it will be able to login with that user and pass)
5)GRANT ALL ON *.* TO root@'%' IDENTIFIED BY 'yourpass';
6)exit
7)It might need to restart your mysql, but at windows i think you can skip this step.
--------------You are done , if you have problem again following the upper steps it will need some configuration at .ini of the mysql , let me now and i will show you how to change it.
I hope that helped you . If you have any question feel free to reply.