win2003 exchange 2003 installation

Hi,

I have windows2003 over which i am trying to install exchange 2003. I went according to the intructions of installation and tick marked all until i reached the "forestprep" utility. When i run that an error message comes that "Either your accout does not have the schema admin permissions or the active directory is too busy at this moment"

I am installing this with the administrator account. I checked the schema admins group and my admin account offcourse is it's member. I was wonder in the services where i could find the "Active Directory Service" which is too busy as the error meesage said.

Please help.