Videos look bad in fullscreen than window

[Versatile2820]

When ever im watching youtube videos in either 1080p or 720p they look good in window mode but when ever i switch to fullscreen the detail is reduced not by alot but still noticeable. Is there a fix for this?

 

[Maguscreed]

My first suggestion would be to try a media player other than window media player to see if the problem is just media player settings.
VLC is a good free one. It's actually what I use primarily now.
VideoLAN - Official page for VLC media player, the Open Source video framework!

 

[Shark007]

For people unable to resolve playback issues in Windows, using VLC can be a god-send.

I suggest you try updating your DirectX drivers from Microsoft.