LiteC language is harder than c-script at some points, but is closer to other commercial programming languages - if you know LiteC, you can easily move to C\C#\(other c-based languages) and vice versa.
Why do you need to change window pic anyway - if you're creating a free game\aplication, you should have no worry about it. It's not ugly or anything (also, unlike many loading screen windows it tells the user how it's going, and that is good). If you are going to publish a commercial product, you should buy a legal edition of GameStudio. Else it's illegal.
