The solution to this problem, as regards the implementation of Blackra1n is quite simple. It will simply copy the executable of the tool designed by GeoHot Common Files within the directory located within Program Files. More precisely, the paths to copy the executable Blackra1n depending on the version of operating system currently in use are:
Windows 32bit: C:Program FilesCommon FilesAppleApple Application Support
Windows 64bit: 64 Bit – C:Program Files (x86)Common FilesAppleApple Application Support
Once copied Blackra1n in the right path you can run it from there or create a desktop shortcut to solve the problem calmly and run the jailbreak.
Video:
I wanted to propose this guide because many people still need Blackra1n for older idevice.