Since I upgraded my monitor to a 4k, I can't take full screen screenshots anymore.
My current resolution is 3840 x 2160, but when I press print screen, it only takes a 2560 x 1440 portion of the screen from the top left corner.
I think it may be due to some scaling windows is doing to the UI so that everything is not too small, but I don't want to make everything small either.
I didn't find any good info on Google, only results talking about how to take a screenshot bigger than your resolution, like how to take 4k screenshots while being in 1080.
If it's related to my graphics card, I have an Nvidia GeForce GTX 660 Ti and my monitor is connected through a display port.
Also, I'm talking about screenshots of desktop or common applications, not games or other fullscreen applications.
Also if I try to screenshot only an application such as a Chrome window using alt+print screen, it takes a screenshot of the right size (of the browser), but it's offset to the left and top.
Edit: I have a screenshot software installed (Purrint) that is auto-saving my screenshots, but I didn't think about it, because I was pasting my screenshots in Photoshop, turns out it was modifying the screenshot in the clipboard as well or something.
Best Answer
Having worked in 4K on the very same graphics adaptor, its not your graphics adaptor. You've mentioned running a third party screenshot tool and its not working well.
Its basically due to the interaction of display scaling and software that does screen capture. You could go with native screenshotting tools or my answer for this question would work as a workaround.
Essentially to get purrit to work, find the executable, set it to disable display scaling for that application, and it should work fine. A longer term fix would be to bug the author to support modern display scaling and all those lovely things. Interestingly, this is probably a bug that would affect any non dpi aware/older screenshot/capture tools.