When you say “output” - do you mean DT is not displaying on the screen? Or are you not seeing debug output? That’s strange, unless you’re directly running darktable instead of first running “cmd” and then running darktable from within a command prompt.
Not sure… I almost never fire up my Windows partition and don’t run DT on it. I guess on Windows Intel must have some sort of closed-source compute runtime other than Beignet and NEO, as Beignet remains blacklisted on all platforms (I’m not going to try and have this changed, anyone who is running hardware not supported by NEO is likely running hardware that will be simply problematic for OpenCL) and NEO remains blacklisted under Windows (someone else will have to take more data to show that NEO on Windows is OK - given that NEO is only formally released for Ubuntu-based distributions, Windows + NEO is a huge unknown. It may turn out that it too was unfairly blacklisted due to darktable’s kernel caching issues, but I was only comfortable removing the blacklist for platforms I personally tested.)