Have you started using Group Policy Preferences lately to manage your Windows 7 and Windows 2008 computers? It is possible that Group Policy Preferences can cause increase in login times in your environment if security groups are used for targeting preferences. For example, you may be mapping drives based on user security group membership(ex: sales, finance, etc). Per AskDS, when a security group is used for targeting a group policy preference setting, the computer has to make several round trips to domain controllers to verify the user group membership. This trip time depends on the kind of connectivity you have to domain controllers and the load of DC. If you are on a Wan link, the trip time may be even more. The windows 7/2008 computer won’t allow you to complete the login until this preference setting is evaluated and applied. In such graces the logon time will increase drastically which is a very bad experience for end users.
The AskDS team suggested using Organization Units instead of security groups for targeting. Usage of OUs will reduce the trips to domain controllers as the GPPs have to just parse the DN text of computer/user account to verify if a setting is applicable or not.
After reading the AskDS article, I wondered why they(MS) didn’t use security tokens for evaluating computer/user group membership at the time of processing the target. It is very easy and less traffic to domain controllers. It makes sense. Isn’t it?
I question was answered in very short time in the form of another AskDS article. They exactly implemented what I felt. MS release hotfix(http://support.microsoft.com/kb/2561285) which injects this nice feature into Group Policy Preferences which can reduce the user logon times and computer startup times(if you are using security group targeting in computer GPPs).
So, if you are using Group Policy Preferences in your organization, then make sure that all your Windows 7/2008 computers have this hotfix. Otherwise one or other day you will end up looking for it when you users keep complaining about slow login issues.