Most ransomware is pretty primitive stuff and can be written by a child. It is often only slightly more complex than the old basic joke-command "10 goto 10". It works well in Windows XP because that was that last version to still have a DOS start-up command, so anyone with a knowledge of how to write a batch start-up command can get rid of such ransomware - or conversely, write it in the first place, telling the PC to display a ransom note with instructions. If you can place a simple display command in a 'startup.bat' file, you too can earn £37,935 by Monday! To get rid of same - Put a DOS boot-up disc in the floppy or CD drive and boot-up from that. Enter the offending startup.bat file on the root directory and find the naughty command line and delete it. Job's a goodun! Now all I have to do, is work out how to get a ransomware notice into Windows 10 . . .