Looks like you have your BIOS writing a cache (video probably) and Windows wrote something into that space allocated for the cache (which is something your mobo mf should have warned you about).
Boot caches help your machine initialize faster by keeping generated information somewhere so it doesn't have to be processed each time. Problem is, this sucks up some memory spaces, which the OS can't really "see" so you can run into conflicts. Your mobo manual should state a warning about this.