Been awhile since I have been here. But I have this process pretty well licked, as I stated a way while back I had to figure out to deploy this Windows 10 Preview/"Update" for my companies IT. We use HP elitebooks for the security aspect.
1) What is the unkown error message; and can you take a screenshot/snip and post it in the response?
2) You need to uninstall ALL HP Protect Tools entirley from the system.
2 A) Are you able to uninstall all HP Protect Tools & Componets from the Add/Remove Programs? If not, you type out which HP applications you do see in list in you response to me.
2 B) Please provide Version Numbers of each HP Application!
3) If you are able to get the HP Protect Tools off the computer, upon final restart, you should be able to upgrade. Then go to the Drivers page of your laptop and install the HP Protect Tools (if they are available)
Let me know how things go. I will check back here frequently over the next week or two