I just tested your code via the following steps:
1. Open a command prompt
2. Launch Regedit (my user context - NOT a local admin)
Confirm that the TaskbarAi value does not exist.
3. Create rtest.kix with "Break On" followed by your command copied/pasted.
4. Run rtest.kix - refresh RedEdit - confirmed that the TaskbarAi value is set
I'm using Kix 4.66, running an x64 platform as a non-admin user.

This worked without any issue.
It's not really possible to create two identical entries in the registry, so there needs to be some subtle difference. Spelling? Space? Special Character?

Make sure your script is saved in ANSI format, not UNICODE, delete the two values and tru your script again.
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