djsolidsnake86, welcome to the XnView forum. You have posed several questions in your post, please make sure you post one post per question next time. Responding is much easier, then. Please see also
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Ok, now let's have a look at your issues:
djsolidsnake86 wrote:i have this problem: with big images (like 1900x3000 pixel) when i open the image, is visualized correctly but if i zoom with wheel of mouse i see the image with stepladders..
how i can fix it?
(for example with image viewer of windows i don't have this problem

)
No clue what it is going on. Sounds like a redraw problem of XnView and/or your graphic card. Does the problem also occur on other computers (with the same image)? Perhaps updating the driver of the graphic card could help. Just a guess...
djsolidsnake86 wrote:another thing: is possible to hide the menu bar (file-modify-visualize-image.. etc) ?
In menu "View" you can hide toolbar, statusbar, but not the menubar. But you have fullscreen mode which will hide everything. Select "View > Fullscreen or simply press 'F' to enter fullscreen mode.
djsolidsnake86 wrote:is possible to hide the button on the top at the right (the little button for close.. minimize..) ?
It's not possible. But there's the fullscreen mode...
djsolidsnake86 wrote:is possible to set the size of enlargement of wheel of mouse?
In Tools > Options > View you have a setting "Change zoom in fixed steps". This setting will change the Zoom behaviour, perhaps this helps.
djsolidsnake86 wrote:thank uou and sorry for my english!
You're welcome. I hope I got you right, otherwise please holler
