Check those local policies
ByRecently I got a call from a client whose Windows XP workstation would not respond to a remote connection attempt through Remote Web Workplace. Specifically, the error was “The local policy of this computer does not allow you to log on interactively.” My client had gone through and looked in the usual places on the workstation and found that it appeared to be configured correctly.
So I connected in and looked at the local policy of the system and found the problem:
In the local policy, I looked in Computer Settings | Windows Settings | Security Settings | Local Policies | User Rights Assignments and checked the Allow Log On Through Terminal Services security settings. There was one item in the list, and it was HelpCenter. So I went in and added the default entries for an SBS configured XP workstation: Administrators and Remote Desktop Users.
Once the local policy applied (after a few runs of gpupdate /force and a couple of reboots for good measure) the user was able to access the workstation through Remote Web Workplace as expected.