Enabling this means uReset will be used rather than SPR in cases where the user's setting can't be resolved, and the computer affected is in an environment where both uReset and SPR might apply.
If set to disabled, or not configured, uReset will be preferred.
if set to enabled. SPR will be preferred.
For instance, when displaying the "Password Reset..." link on Windows Logon screen, this setting determines whether the Password Reset URL will be uReset or SPR.
Normally, this should not be set.