Disk Defragmenter doesn't check C:
I've used the Win 7 built in Disk Defragmenter since day one. Noticed about two months ago that it is not checking C:. It checks the other included drives (an external HDD and a Recovery drive) on schedule.
I have tried unchecking and rechecking and changing scheduled times all to no avail. As a workaround I manually analyze the drive...when I remember. Any idea why the program stopped checking the most important drive?