Windows Server 2008 will detect the speed of a client's connection to the network and, based on its measurements, disable enforcement of certain policies that would bog down a slow connection. Policies that Windows will disable include disk quotas, folder redirection, scripts, and software installation and maintenance. By default, Windows considers a speed of less than 500 Kbps a slow link, but you can change this on a per-GPO basis.
To change the slow link threshold, follow these steps:
Edit the GPO for which you want to change the threshold in the Group Policy Management Console.
Navigate through Computer Configuration or User Configuration, as well as through Policies, Administrative Templates, System, and Group Policy.
Double-click the Group Policy Slow Link Detection policy in the righthand pane.
Click the Enabled option, and enter the connection speed you want to be the new threshold. Enter 0 to simply disable slow link detection.
Click OK when you're finished.