I have cnc fiber laser cutting machines it has operating software cypcut and I need to change it to Mech 3 or 4 do I have to buy the driver card with the software or only the software?

Mach3 and Mach4 typically use specific controller cards that are compatible with the software. If your controller connects to your computer using either a USB or Ethernet connection, then you will probably need to change the controller card as well, unless your controller card contains a plug-in that works with the Mach3 or Mach4 software.