Hi Arnaudd1, I understand your concern. Those subkeys in HKLM\Software\Microsoft\Enrollments are normal. Windows creates them to support device enrollment features like Azure AD or MDM. They do not mean your PC belongs to a company.
To check if your device is managed, go to Settings, Accounts, Access work or school. If you do not see a work or school account listed, then your PC is not linked to an organization.