In the grand scheme of supercomputers, a homegrown cluster constructed by Microsoft is just a boy among men. However, said rig has set at least one record by becoming the "fastest-ever Windows HPC cluster." At the International Supercomputing conference in Dresden, Germany, it was announced that this beast ranked 23rd in the world "with a problem-solving performance of 68.5 teraflops." The National Center for Supercomputing Applications utilized a beta version of Windows HPC Server 2008 to hit the aforesaid mark, and if you're curious as to what it took to get there, try 9,472 cores of processing power. There's more where this came from for the hardcore nerds in attendance right in the read link.