Update 9/13/2012: The problem has been fixed in the August 2012 Cumulative update for SharePoint Foundation.
I have recently come across an annoying problem, and I have seen it often enough that I decided to blog about it. Consider the following scenario:
You open your SharePoint Central Administration Website and it takes a long time to load the first time. After the initial load, the site is responsive and pages load and open fast. If you are experiencing these symptoms, you have come to the right place. Continue reading!
Why is it Slow?
In the process of initializing the SharePoint Central Administration website, SharePoint tries to find the security group IIS_WPG. It first checks the local computer for the group, if the group is not a local security group, SharePoint tries to find the group on the domain. If you have a lot of two-way trusts, this search can go on for several minutes, which is what causes the slowness when loading the site.
IIS_WPG: Do I really need it?
Why does SharePoint need IIS_WPG – that’s a different topic. This group used to be a local security group on the default installation of IIS 6 (Windows Server 2003) and SharePoint 2007 (MOSS) would add the SharePoint application pool accounts to this group. I don’t know what problems you will run into if you delete the IIS_WPG group in MOSS 2007/WSS 3.0, but you should definitely not delete it.
The IIS_WPG local security group in Windows Server 2003
The group went away with IIS7/Windows Server 2008, but SharePoint still tries to find it, which is what creates the slowness. This behavior is same for both MOSS 2007/WSS 3.0 and SharePoint 2010
The solution in this case is simple. All you need to do is create a local security group named “IIS_WPG” on each SharePoint server in the farm, and after that, central administration web site should load without any delays.