First of all the Screenshot is MS-SQL and your talking about MySQL, these are two Very Different Products, wont clash with each other (if thats what you meant) etc.
The Screen you have just Shown us is it is asking for an Account that EXISTS on your computer / Domain which has the Authoirty to start the MS-SQL Service, so that every time you switch on your computer, it uses this account to Start the Server Serives. You could have just picked LOCAL and it would have continued or you can type in your password if your Account is Admin type.