No. You already have a 3pin. Your motherboard is setup to control 4pin. Go into bios and change the fan control from pwm to auto/voltage for that header.
You just need to setup the motherboard/bios for the equipment you want to use. If you buy a pure wings2 pwm, then you'd not need to change the mobo, but if that pure wings2 is a 3pin, then you would still need to make the change.