I recently purchased a laptop with a 4K screen and really loving the crispiness but also the customizability regarding text and ui sizes Windows 10 provides, which makes it more useless then the simple retina solution on Macs. One issue I though stumbled upon was kinda old software not playing well with this mega resolution, particularly Photosho CS5.5 .
Luckily, a guy named Dan has a easy fix, http://www.danantonielli.com/adobe-app-scaling-on-high-dpi-displays-fix/ , which involves editing the registration database to permit a external manifest to dictate how the app should behave on high res screens. The manifest file is the same for all apps they just need to be named the same as the executable, so photoshop.exe should be photoshop.exe.manifest . Beware that sometimes the windows update makes change to the registration database but then you just add the entry again in :
HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows > CurrentVersion > SideBySide dword : PreferExternalManifest with a value of 1 .
Download the manifest file here (credit goes to http://www.danantonielli.com/ )