how can i update HKCU with powershell script

How are you going to apply this script?  Depending on the way you might be able to leverage Group Policy.

we are flexible and open to options. thx

If you plan on running your script on a manual per user basis or logon script. I would recommend using Group Policy Preferences. You will find it very intuitive and not need to know scripting and get the same results.

I recommend searching the Internet on how to regarding this. If you run into a wall I will see if I can assist tomorrow.

I am currently on my phone so I am limited at posting instructions and examples.

Mike

I'm going to repost this question and would appreciate it if you don't respond to my new question. I am very familiar with GPO's this question was specific to custom powershell scripting.

I've requested that this question be closed as follows:

Accepted answer: 0 points for siber1's comment #a40875530

for the following reason:

reposting

Reposting will not help because your query deals with HKCU which means it must run by the logged in user to make changes to their own setting, you can not do it in bulk.
The direct answer to your question in the way you framed is no, you can not.

If you are looking at a script going through user profile folder on them server loading ntuser.dat and making the change it is a different story.

Your comment to the offered solution by an alternate approach is a rather objectionable and disrespectful to yo_bee.

You should include what the change it is you want to add.

@siber.  I am open to helping you and I felt that if you gave some more detail about what you were looking to accomplish we probably could of came up with something.   Sorry I was not able to help.

Good Luck on your task.

Mike