Ragnarok online on win 10?

I can't get the game running on my laptop. My laptop has

Intel i7

32gb ram

Ultra hd

Can someone help me get the game up and running?

More infos helpful (hardware, what is the problem us.w.)

Intel Core i7-7820HK (2.90 GHz)
17.3 "UHD LED AG Display (3.840 x 2.160)
32 GB RAM (2 x 16 GB)
1TB SSD PCIe NVME M.2
1TB HDD SATA 7,200 RPM
NVIDIA GeForce GTX 1080 (8 GB GDDR5 dedicated)
Windows 10 Home (64-bit)

The problem is simple, I do not get the picture on full screen no matter how I change the settings. There's a small box with a part of the game. I can't pull it too long or anything. I have to say this is also an older online game but it is still online and well attended.

Press Alt + Enter if you do not get a fullscreen. Solves most window full screen problems.