"In/Out of Context Menu Icon: Exploring the Distinctions"

I have noted a discrepancy in the context menu for .reg files between two machines. On one machine, the Edit option opens with an icon representing a text editor, rather than the standard Notepad icon, which is correctly configured as the default text editor. However, on the other machine, the Edit option opens with the expected text editor icon. I am intrigued by this difference and would appreciate any insights on why this variation exists. Rest assured, I am prepared to rectify the issue once the cause is identified.