Hello, thank you for reaching out to Microsoft Q&A.
Could you please share a full screenshot of the error message you see when enrolling in ESU for our reference?
Also, type "Winver" in the search bar on the taskbar and press Enter.
Post a screenshot of the resulting dialog box.
Meanwhile, ensure you have installed all the latest updates for your Windows 10 PC.
Go to Start > Settings > Update & Security > Windows updates > Check for Updates.
Let me know how it goes.