Windows creating a partion on mechanical hdd rather than ssd

[opethdisciple]

I have just knoticed that what ever I try Win 7 refuses NOT to create a 100mb partion on one of my mechanical hdd, even when I am installing the OS to my SSD.

Any idea what this partion could be?

Windows and all apps are on the SSD, but there is a 100mb system partion on the mechanical hdd.