When connected, my Zebra printer the S4M is recognised by Windows with the "ZDesigner S4M-203dpi ZPL" driver and I'd like to use the EPL Driver "ZDesigner S4M-203dpi EPL".
I tried to install it manually, delete the ZPL driver, use the Zebra utility setup, upgrade the firmware to the last version but I didn't find the switch option.
I found one answer : http://www.fixya.com/support/t1950296-zebra_sm4_label_printer_change_zpl_epl
You will need to change the firmware on this printer in order to be able to change the language. I don't believe this printer will allow you to change the language using the advanced options in the menu unless they have recently changed this.
I found also a web page which proposed to download old driver for the S4M but I prefer to avoid it. http://www.jamfrance.com/site/support/download.asp?categorie=13
Note : To verify if the EPL driver was working, I used a custom application which send EPL data and I tryied to use Zebra firmware downloader which have 2 interesting options : Send EPL page and Send ZPL Page. You probably guessed, only the ZPL page works.
well i found the solution : https://km.zebra.com/kb/index?page=answeropen&type=open&searchid=1324718583535&answerid=16777216&iqaction=5&url=https%3A%2F%2Fkm.zebra.com%2Fkb%2Findex%3Fpage%3Dcontent%26id%3DSO8156%26actp%3Dsearch%26viewlocale%3Den_US&highlightinfo=6292684,73,91#
The EPL firmware is listed in the Special Firmware section on Zebra.com.
I have to install the special firmware of the S4M and it works .. it's sad that they don't explain the "Special" term (and in the release note also)