Hello,
Thank you for posting in Q&A forum.
There may be several reasons for the unavailability:
Permission problem: Your user account may not have sufficient permissions to access the registry key. Try running the registry editor (regedit) as an administrator and check again.
System configuration problem: Some special versions or configurations of Windows systems may not have the ProductName key in this path.
Missing registry key: The key may have been deleted or moved due to system damage or some software modification.
Operation error: Confirm that the path is correct and that you have correctly checked the relevant registry branches.
You can try the following steps to solve this problem:
Run the registry editor as an administrator: right-click the Start menu, select "Run", enter regedit, and then press Ctrl + Shift + Enter to run with administrator privileges.
Check the path: Make sure that the path is entered correctly and do not miss any part.
Check other paths: If this path does not exist, try to find the ProductName key in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion.
I hope the information above is helpful.
Best Regards,
Yanhong Liu
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