Here is a fresh set of diagnostic information queries for SQL Server 2008 and 2008 R2 for December 2011. Some of the queries (which are labeled) will only work with SQL Server 2008 R2 Service Pack 1 or later. Most of the queries will also work with SQL Server 2012, but a few will not because Microsoft made some breaking changes to several DMVs between SQL Server 2008 and SQL Server 2012. If you have SQL Server 2012, you would be better off using the matching version of these queries meant for SQL Server 2012.
You will need VIEW SERVER STATE permission to run most of these queries. I recommend that you run each query separately, after reading the instructions and comments. One new feature is links to the Microsoft KB articles that list the builds for each branch of SQL Server 2008 and SQL Server 2008 R2.
I always like to hear your comments and suggestions about these queries.