Hp 8710 Officejet pro "Scan to Computer" issue - Solution

[Seratoz]

Hey guys,  I recently ran into an issue where my "scan to computer" would no longer function on my Hp officejet 8710.  I believe I may have found the root cause for MANY of you as I see quite a few posts about this.  Most of the posts recommend re-installing the software after a full uninstall etc and running the "Print and Scan doctor".  In my case the printer works just fine for everything except scan to computer.

The Issue:

       Scan to computer (FROM THE PRINTER) doesn't work for networked computers.

Observations:

       I found that there were actually two issues when this happened.  I could still "scan" if I initiated it from the computer using HP Smart, but none of the remote Scan to Computer functions worked..... baffling to say the least.  And my old computer where this was initially setup works just fine. 

      This led me to believe that it was linked to the computer itself.  Upon further inspection/digging I found two remarkable things.  The WIA (Windows Image Acquisition) service was stuck in the "starting" state.  No matter how long the computer was turned on.  AND the default software installed by windows is NOT the FULL software installation which supports scan to computer <--- this part is EXTREMEMLY baffling why microsoft/HP would not give the option of FULL software installation.  Even going to HPs drivers website only "installs" a shim that then says "oh hey, go get it from the microsoft store", which is of course...... hp smart and not the full install......  I personally re-installed the software multiple times, and even installed/re-installed the FULL install (using the method below) multiple times but it did not fix the scan to computer problem.

      So two issues:

1. Not full Software
2. WIA stuck in Start state.

The solutions (and possible causes):      

To get the full software:

       The only way to get the FULL software install is to instead run "HP print an scan doctor" which will default to "HP Smart" but give you the option of choosing the full software.

To get WIA out of the stuck state (and background involved):

       I did a good bit of digging on this to diagnose why WIA was stuck in the starting state (when it is in this state you CANNOT start or stop it).  It is infinitely in the "starting" state.  I looked at the event logs for windows and saw the output sti svc in the ERROR log for WIA failure.  Based on this I looked up what sti svc is and does, it is for "still image devices" i.e. scanned pictures.  Turns out that when a device is connected to the computer it loads a vendor supplied STI.INF file which configures a few things related to "still image devices"  i.e. scanning capability related settings.  You'll notice here (as I did): https://docs.microsoft.com/en-us/windows-hardware/drivers/image/inf-files-for-still-image-devices that those files are only configurable for USB, SCSI, and SERIAL.  Interesting to note there is no (network -  or wireless network - installed) option.....  I am no where near an expert, but based on that, I connected my printer the to computer by USB, and re-installed.  My assumption being that the STI.INF should be supplied correctly.  This time around.  and what do you know...... WIA started successfully, and I was able to scan to computer.  I moved the printer back to wireless.... and I could still scan to computer.  It appear this failure for WIA is bound to stisvc, and that stisvc is configured by STI.INF DURING INSTALLATION, meaning once this is installed and configured ONCE via USB, you can then move the device back to network or wireless and keep working.  This makes is extremely annoying for a household where you may have mulitple computers, and you have to "LOCALLY INSTALL" the printer on each so that the STI.INF file is supplied and WIA works properly for each.

LONG TERM SOLUTION

1.  Ok at this point, HP should make full software easy to find an install, no matter what you select here: https://support.hp.com/us-en/drivers/selfservice/hp-officejet-pro-8710-all-in-one-printer-series/790... you can only install HP Smart.

2.  I don't know if the issue for the WIA and sti.inf file is a microsoft issue or an HP issue, and I'm not even sure if its truely the issue, but what I can say is, I used the solution for #2 above on three different computers experiencing the same issue, and it worked every time.