"While I'm playing a new game of mine on my computer, the sound is not synchronized. Do I need to buy a sound card for it?"
You didn't tell if the BIOS and motherboard drivers are current. Some think that a new board would have a current BIOS and the CD would have the latest drivers. (NO) Some think that Microsoft provided "Driver Update" and that would work. (NO) And some think Windows Updates provides good drivers (NO!)
You need to cover this off before you disable the onboard sound and get a PCI sound card. My suggest is the PCI SB16 by Creative Labs. It's not much and is a "standard".
Okay. I built a new system for myself so I can get better graphics and such for games and normal use. I have a P4 3.0Ghz, 160GB WD HD (Partitioned to 30, and 130), PC3200 512MB DDRRam, Nvidia GeForce FX 5600 256MB video card, and Windows XP Pro SP2. While I'm playing a new game of mine on my computer, the sound is not synchronized. Do I need to buy a sound card for it? I don't use surround sound, so I don't need fancy; just need something to make this work. I've done defrag, and scan disk, and nothin makes it work right. Would my LCD monitor be causing it? Watching videos is fine, it's just games. Any suggestion? By the way, it works fine on my laptop (Sony VAIO, 2.8, 768MB DDR, 30GB, 32MB ATI video XP Home SP2).