In June 2006 Microsoft in conjunction with NCSA completed a Top 500 benchmark on a 900 processor Dell PowerEdge 1855 cluster running Windows CCS Version one. The result was a 4.1 Tflop Rmax number; placing this cluster at number 130 in the July 2006 Top 500 List. This was a significant accomplishment for an offering focused on a design point of 64 nodes.Attend this session to hear about our experiences compiling and running the HPC Linpack benchmark in a large-scale Windows environment with CCS. We will cover the design of a large Windows cluster, the tools used to provision the cluster, the tools used to compile the benchmark, the job submission process for the parallel execution of the program, and the actual results. We will also talk about what we learned from the process and how that information will lead to improvements for future versions of CCS.