Rectangular chessboard squares

I don't think it's a problem by Lichess but I'm going to ask the question anyway.
I changed my PC and now i see the squares of the chessboard in a rectangular way. Have someone ever had the same problem? How can I fix it?

Here's an example: s11.postimg.org/h846tjek3/IMG.jpg

Hello, what browser and browser version do you use?

Hi Aks_Oks!
Right now I'm using Google Chrome version 58.0.3029.110; but I have the same problem with classical IE.

Sounds like you're using the wrong resolution for your screen. That screenshot looks completely normal to us.

support.microsoft.com/en-ph/help/14108/windows-7-change-screen-resolution

you click on the screen and then on "toad" it will take you to the desired page.

I fixed it. Thanks Clarkey!
I was using 1600x1200 and now with 1600x900 it is completely fine.

Lichess looks fine on the mac, but unfortunately it doesn't matter what screen resolution I choose for my windows 7 screen, it either tells me wrong input, or it looks bad.

Anyway, glad it worked for you @eydiab :)

youse the chimp setting in turtoise mode.