The problem got fixed after I restarted my PC again after updating the virus signature database version to 12105 (20150817).
So basically the fix (after upgrading to OS 10) was to set ESET to pre-release updates, restart PC, update the signature database and then restart again and HIPS was enabled.
And now I also updated the product version to 8.0.319, thanks for letting me know Marcos.
Regards!