In windows 8, I have a windows file system driver which is signed by microsoft. It works fine. And I notice that there is a folder for my driver in the folder Windows\System32\DriverStore\FileRepository\
But, after I update my windows 8 to 8.1, the driver can not be loaded and windows complains that the driver is not signed. And there is no folder for my driver any longer in the folder Windows\System32\DriverStore\FileRepository\
Does anybody know what's the reason that 8.1 doesn't remain my driver files in the folder Windows\System32\DriverStore\FileRepository?