I had this exact same issue starting a couple of days ago under Windows 7 Ultimate. First the screen would freeze 5-20 minutes after boot, followed by mouse. Seemed random. Only solution was to unplug computer and power back up. I disabled Web protection and ransomeware protection on Malwarebytes and have had no freezing in last several hours.
I think this was associated with freezes:
Event 219, Kernel-PnP
The driver \Driver\WUDFRd failed to load for the device WpdBusEnumRoot\UMB\2&37c186b&0&STORAGE#VOLUME#_??_USBSTOR#DISK&VEN_GENERIC&PROD_USB_CF_READER&REV_1.01#18E3312D81B&1#.