Active Directory Group Policies refresh every 90 minutes on a client (with a plus/minus 30 minute offset). If you want to force a refresh remotely on computers, you can use a utility called psExec from Sysinternals. psExec allows you to execute programs on a remote system interactively.
Download psExec and at the command prompt execute the following command:
psexec \\computer cmd
where computer is the IP address or name of the remote computer
Assuming you have the proper access to the remote computer, you will be able to execute the commands you want remotely. For example, to force a Group Policy refresh type gpupdate /force. The command will be executed on the remote computer instead of the local machine.
Another option is to use RGPrefresh.exe from GPOguy.com. This is a free command-line tool which requires .NET Framework 1.1. Click here for more info.
And yet another option is to use a free add-on to Active Directory from the Special Operations Software called Gpupdate. This tool will let you remotely and graphically refresh Group Policies as a right-click option in the user interface.
