The following is for Windows Download Putty Choose serial and select the COM? you can find the com number from device manager under [Ports (COM & LPT)] Now that we have a serial connection go ahead and plug in the netinstall iso usb drive created using Rufus from Debian website hit tab to enter cmd to boot remove quiet after the --- and replace with console=ttyS0,115200n8 example below. This will make the installer use the serial port