An update:
After seeing that the prints from this new Windows PC were printing lighter than those form either Windows 7 or Window 8.1 machines, I wanted to check a second Windows 10 PC to ascertain whether or not there is something unique in the operating system and/or how talks to a printing app in conjunction with the printer driver. For that I borrowed a random laptop from a friend, a run-of-the-mill Dell laptop for home use with Windows 10 installed. I wanted to see how that stacked up against the others. This laptop has no monitor calibration/profiling done whatsoever.
In order that I can remove any potential conflicts with color spaces, color profiles and the like, I created a completely new un-tagged test target file in Photoshop. Additionally, I downloaded and installed the Adobe Color Printing Utility (ACPU) on each of the computers so I can print without color management. Also, installed were the HP B9180 printer drivers appropriate for the installed Windows version (Windows 8.2 and 10 both share the same driver version as per HP recommendation.)
I then printed the target on each computer side by side, one after another, on the same HP Advanced Photo Glossy paper using ACPU under identical conditions. Within the Printer Properties dialog, Application Management was specified and a generic gloss paper type selected to instruct the printer to deposit the right (PK) black ink (custom created without any profile attached so there is no chance of some sort of conflict.)
The results are as shown in the attachment.
As can be seen, #1 and #2 from Windows 7 and 8.1 respectively are identical, visually as well as statistically by measurements in Photoshop. On the other hand #3 and #4 are also identical, but they are both easily discernible as lighter than the other two.
At this point I am not sure what to think. The consistency of discrepancy is intriguing. Obviously, there is something going on that is related to Windows 10, if not inherent to it then may be in how it talks to the printer or vice versa. I don't know what happens when ACPU hands off the file to the printer for it to be printed but somehow the signal from Windows 10 is to put less ink.
To eliminate the role of the printer in this behavior, I would have to get a different printer (which I don't have and which would be hard to borrow.)
I have done extensive searches both on internet at large as well as LuLa forums and have come up empty on anyone talking about seeing anything like this. The question is if anyone can repeat the comparison (at least between an 8 machine and a 10 machine) side by side on a different printer. Any volunteers out there?
Thanks.
:Niranjan.