When I attempt to set the time as follows:

NET TIME \\127.0.0.1 /SET

it works correctly.

When I attempt to set the time thus:

NET TIME \\local-ip-address /SET

I get the error message:

System error 5 has occured.
Access is denied.

I've verified that the FOLLOWING Group Permission is in effect and applies for the user in question:

Local Computer Policy + Computer Configuration + Windows Settings + Security Settings + Local Policies + User Rights Assignment + "Change the system time"

The Windows Time Service is started.

(both probably obvious because the loopback works)

"local-ip-address" machine has "Enable Windows NTP server" group permission enabled.

The error occurs REGARDLESS of whether the Firewall is enabled or disabled.

Windows XP SP3, Workgroup networking. A different client machine in the workgroup works, no problem.

Is there another Group Policy or Registry value that applies here?

Thanks in advance for your time and consideration.You lack administrator permsI think he's well aware of the cause - he's setting local policies and wants to know which setting needs to be changed.

As for the OP's question - it WOULD be a network permission I think, to utilise 'net time'.