You have to change the "compatibility settings" for JabRef to "Disable scaling for high DPI settings". Further information is available at https://www.microsoft.com/surface/en-us/support/apps-and-windows-store/app-display-issues?os=windows-10
You can directly use the references in Word's internal reference manager. Short explanation: Export your bibliography in XML format and replace the Sources.xml in
%APPDATA%\Roaming\Microsoft\Bibliography. Long explanation: see Using JabRef references in Word document. See https://www.youtube.com/watch?v=2PpLZTol9_o vor a video explaning the usage.
Start regedit and create the following key: