First of all, why would it need to change anything? Second, that's rude. Just because I'm not a computer geek does not mean you get to call me a moron. If I started asking you a bunch of things about music or medicine I bet you wouldn't know much about that. If you want anyone to take you seriously, be nice to them. You could just answer nicely and explain or just leave it alone.
well.... most programs you download have to ask permission to change things on your harddrive, like google chrome and stuff. It's to install the program. I don't exactly trust this download to the fullest, but you should only be skeptical of installations when you have no clue where they came from. Or if they have sketchy file names like "Setup.exe." Most of the time your antivirus will catch these before you give it permission.