No need of any script to run. In Windows Server 2008, there is an option in Local Security Policy. Click on Start and then Administrative Tools and then click on Local Security Policy. In Local Security Policy, click on Account Policies and then click on Password Policy. Under Password Policy, double click on “Password must meet complexity requirements” and then select the Enabled option. Then click on Apply and then click on OK. Then close the Local Security Policy and then close the Administrative Tools window.