I would skip the onboard soundcard entirely. Look for an entry level soundcard as Tim O'Brien advised (about a hundred bucks), install it and then go to your computer management software and set that as you system soundcard - literally turn off the motherboard card if you can. Deal with the soundcard's inputs - you have a preamp right there.
Look at Reaper for software (google "reaper sound") its inexpemsive, powerful and stable.