Add an EXE to the Path variable for command line access.

  1. Windows + X
  2. System
  3. Advanced system settings
  4. Advanced
  5. Environmental Variables…
  6. System variables
  7. Path
  8. Edit…
  9. Append a semicolon followed by the full path to the directory that contains the EXE
  10. OK, OK, OK

;C:\Program Files (x86)\OpenSSL-Win32\bin

In step 9, sometimes is easier to copy and paste from Notepad before and after editing the Path.