What is it that you are trying to do with the remote in Windows 7? Are you in the "Media Center" program of Windows 7 and trying to use things like arrows and fast forward and pause and so forth? If so, I think that is what the registry change you mention is for. I think your Xbox media remote sends out code 8 while a normal Media Center remote sends out code 1 (although remote can be changed by a button press procedure). So you change that registry entry from a 1 to an 8, then save and reboot. There are also other ways you could change the registry, I think that 0 means accept any code, or you could change the 2 3 or 4 to the 8. I could be mistaken but I think the Nuvoton CIR part is the lower level hardware driver and the eHome part is a higher level portion (intended for Media Center).
Having said that, the NUC seems to also have some special case for powering on from the remote - and the most recent BIOS version was needed for that power on function in the case of the Xbox remote (code 8). I have been unable to find out how to control that power on feature. Power on seems to react to all codes (1-8) rather than being able to selectively program the codes like you can in Windows. It is also powering on when the Pause button is pressed - that seems strange to me. I am probably one of the few people who have multiple NUCs in one room, and that doesn't work well like I use to be able to do with multiple Intel non-NUC PCs in a room. The IR has worked fine for a decade like that, powering up only from standby/suspend (and never when the pause button is pressed). But the NUC changed that, they are also powering up from "off" and are listening for multiple codes rather than being selective (and the pause button, which sure seems like a bug).