I installed SimCity 3k through Galaxy, I have installed through installer, and also changed compatibility mode to XP. I have used lower resolutions such as 720, and 768. I'm using an updated Windows 10 64bit Pro.

The issue I have is whenever I run it, it acts like it's running, it will have audio but no video. All I see is the windows and desktop under what should be the game. it also doesn't change my resolution. The building architect works fine and I can use that. However the main game does not. Starting through Galaxy and the desktop shortcut makes no difference.

Does anyone know what I am doing wrong?

You could try running this patcher. So you can get into the menu at least to change resolutions? You'll know that the patcher worked then if you can see the new resolution among the old ones under preferences.

Also, whenever I start a new game I have to minimize the game (that is, alt+tab) and then maximize it again to get an image. But then it runs fine.

Tried that but it didn't work. :( Same issue of the game starting but just showing nothing, not even a black screen. :/

Ah I'm sorry then. Perhaps open a support ticket then.

A reboot went and actually fixed the issue I was having. *rolls eyes* Typical computers. Thank you though for the help! I really appreciate it!

Ah glad to hear it, have fun :)

Thanks. :D