Messed up login

Hi I am looking for a solution to a long ongoing problem with my login screen-the text and login is "stacked" on top of each other or crammed together.

It is difficult to pick out where to click "play" or see the progress of updates.

I tried to post an image but all I got was an error message.

Sorry for being newbish but this really baffles me-can anyone suggest a fix?