Hi,
If you would like to find the old name of the PC before you changed the computer name, you can open Registry Editor and navigate to HKLM\Software\Microsoft\SchedulingAgent\OldName
If you still cannot see it, open Event Viewer.
Press Windows key + X
Click Event Viewer
Expand Windows Logs
Click Security
Filter event id 4648 . Then you can choose the date, and you will see what was the computer name at that time.
For your reference:
https://answers.microsoft.com/en-us/windows/forum/windows_10-security/default-pc-name/6c37b55e-b2fd-4ac2-bd58-33336b93b4af
Thanks,
Eleven
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