See there how to FIX the fullscreen "windowed" problem
Hi everybody!
I solved a problem when spiral knights run fullscreen, you see only a cropped, windowed and in a corner of the screen.
To solve this:
FOR STEAM USERS (100% working):
1) go to your spiral knights folder (usually located at "C:\Program Files\Steam\steamapps\common\Spiral Knights" )
2) go to the folder "java_vm"
3) go to folder "bin"
4) right click on "java" (the icon with a cup of coffe)
5) go to "compatibility" tab
6) check the "disable display scaling on high DPI settings" option
7) click on "apply" and then "ok"
8) right click on "javaw" (the icon with a cup of coffe)
9) go to "compatibility" tab
10) check the "disable display scaling on high DPI settings" option
11) click on "apply" and then "ok"
12) open steam with administrator (right click on steam and left click on "run as administrator")
13) click on icon of steam an click on spiral knights
14) Enjoy!
FOR NOT STEAM USER (maybe not works):
1) find the spiral knights folder
2) go to your spiral knights folder (usually located at "C:\Program Files\Steam\steamapps\common\Spiral Knights" )
3) go to the folder "java_vm"
4) go to folder "bin"
5) right click on "java" (the icon with a cup of coffe)
6) go to "compatibility" tab
7) check the "disable display scaling on high DPI settings" option
8) click on "apply" and then "ok"
9) right click on "javaw" (the icon with a cup of coffe)
10) go to "compatibility" tab
11) check the "disable display scaling on high DPI settings" option
12) click on "apply" and then "ok"
13) run spiral knights
14) Enjoy!
Thank you in advance for suggestions and thanks.
P.S.: I'm not a technichan so, if someone have problems, try to solve by yourself or look for someone that writes the solution in the comments. Anyway, since I'm open for suggestions, when I find a fix comment, I'll put in there! ^^

Hey Lonxx,
I came across your post as I myself am having the same same issue with my full screen. As I do not have steam installed and could not find the file location that you provided I decided to do some looking around. After numerous failed attempts I decided that I might as well click on the shortcut for Spiral Knights. I then found that there was a compatibility tab and clicked on that. I then proceeded to finish off from step 10.
This worked for me and may work for others who do not have steam installed. once again, thank you Lonxx.
Sirrobotic,
So this useful topic it will not be buried