Why does Windows list my SSD system drive as removable?
This has probably happened to you. You right-click the Safely remove hardware and eject media icon, and among the removable devices is your primary hard drive! Surely you can’t eject your primary hard drive. Why is this on the list?
Because the device driver reported that the device was removable.
Explorer doesn’t try to second-guess the device driver. If the device driver says that the drive is removable, then it’s removable.
One of my colleagues reports that whenever he runs into this problem, he installs Intel Rapid Storage Technology, which includes the drivers that fix the problem.