My headphones only have one jack on them but have a built in mic. My comp needs two jacks for the volume and mic to work. Is there any thing i can download my to make it work from one, or do i have to buy a 2male to 1 female splitter
No. The jacks on your PC have three contacts each, the jack on your headphones is 4 pin. There is no software that can magic up a new contact for you, so you'll need a splitter.