General

Computer recently downgraded?

Whenever I try to download a game it finds some way to fail. A pop-up with red words appear and say something like file/startup.exe has failed and I'm getting tired of it. Also since like 2days ago my computer graphics down graded...Like my firefox has a grey ring around it and the exit/minimize/maximize buttons are all old style now. They are grey buttons when they used to be a red exit and the others were blue. What happened and how do I fix it?

I can't download/install maplestory or cortex command. Those are the only games I have tried and they had different errors.
It has 127GB free.