Here is a quick repost of the walkthrough with a few tweaks for SQL 2008 / Windows 2008 (R2) and Sitecore 6.4.x/6.5 (some steps are not required any more):
- Find the application pool that your Sitecore is running under. Open Properties and set the identity to the domain user on the corresponding tab.
- On the SQL Server box register the domain user and grant security permissions on Sitecore databases for the domain user according to the section “4.4.1 Creating a Database Account for Sitecore CMS Databases on SQL Server 2008” of the Installation Guide.
- On the machine that hosts Sitecore add this domain user to the IIS_IUSRS group.
- Adjust the permissions for the IIS_IUSRS group according to these sections of the Installation Guide“:
4.2.2 File System Permissions for ASP.NET Requests”
“4.2.3 File System Permissions for System Folders”.
- Edit the /App_Config/ConnectionStrings.config file and replace the user id and password parameters with the trusted_connection=yes option:
- Prepare your identity so it can be used as a service account with “aspnet_regiis.exe” and the -ga switch.
- Add your domain service account to the local “Performance Monitor Users” group as per this section: “4.2.5 Windows Registry Permissions”
This walkthrough describes basic Sitecore configuration with no modules or OMS/DMS installed. Additional security permissions are required for the modules and other components that carry their own databases.