Pros: The module that is not broken is running well

Cons: I received a bad module, after running some memory test it was obviously a problem with the module as it was writing the same incorrect bit over and over.

Overall Review: The memory is a great value when working. This bad memory module destroyed my operating system by writing incorrect bits while in use. Lesson learned, always run a memory test with your upgraded ram before booting into your OS. Surprisingly enough, Microsoft offers a very nice low level memory testing utility to diagnose these sorts of problems.