It Works! Thank you so much.Here's the thing about Win10x64....
1) Make sure you have Java installed
2) Make sure you have the javaw.exe file in the SysWOW64 folder (DON'T mistake it with the javaws.exe file!)
3) If said file is not in said folder, just copy it from the folder in point 1)
4) While copying the codes from this forum; make absolutely sure you have the correct paths for your file locations - double and triple check it!
5) Here's my code and it worked after several hours of trying (i was missing the javaw.exe in SysWOW64):
C:\Windows\SysWOW64\javaw.exe -Xmx256m -DTW.language=3 -DTW.install.path="E:\Gry\Steam\SteamApps\common\The Witcher Enhanced Edition" -jar TWEditor.jar
Hope this helps and thanks to all who supported this!
(I was missing the javaw.exe file, too.)