Can someone (perhaps the developer?) tell me why my pc will not run it because it could harm my computer? I'm VERY worried that there is something malicious inside my pc.
Don't worry there isn't anything malicious in your PC. I believe Microsoft is considering Juice World malicious is because the program doesn't have any publisher so it's considered unknown. You can run Juice World by pressing ,"Run Anyway." If any other programs in your computer is getting this message you can do some research to make sure it's safe.