To Grandpa68 from another gramps!
As a matter of interest .............
**** (a) Have you seen ANY (or all) of the following 5 files anywhere on your hard disk(s)?
prosync1.vxd, prosync1.sys, sfhlp01.sys, prohlp02.sys, prodrv06.sys
**** (b) What Operating System are you using?
If the answer to (a) is positive, I think it would be best to apply sfclean.exe AFTER you've uninstalled Black Mirror, otherwise you
may (???) get problems with your USB sometime in the future.
However before implementing my 'advice', please get confirmation from somebody more competent than I am, e.g. Jenny100 who is a tech whizz (and very helpful)!