A:\> hddreg.exe (if file is on boot drive root)
A:\> cd HDDREG (if in a folder)
A:\HDDREG> hddreg.exe
HDD Regenerator must run from real DOS, not a Windows Command Prompt.
Solution: Create a bootable USB using Rufus (FreeDOS or MS-DOS) and copy HDDREG.EXE to the root of the USB. Boot from USB and run: Hdd Regenerator Bad Command Or Filename
A:\> hddreg.exe
In modern Windows, if a program is in a folder, the OS often knows how to find it. In DOS, the PATH variable is strictly limited. A:\> hddreg