Graphics issues on PC

Hi there, just found a bit of an issue since I started playing on PC a little. Basically the game looks terrible when windowed. It makes the text harder to read and things in general just don’t look very nice. Is there some way to increase the resolution or otherwise change any graphics options? I have a powerful gaming pc and all my drivers are up to date.

Here’s a screenshot: http://imgur.com/a/wBhlJ

Thanks for your time.