How do you reset computer on 2003 Chevrolet Venture?

There is no "Computer reset" for the 2003 Chevrolet Venture. If the check engine light is on there are several ways to get the code pulled to determine what the problem is. You can take it to a local parts store like AutoZone or O`Reily's. Many places will pull codes for free. Or you can purchase your own code reader and pull codes yourself. There are several different kinds. They range from cheap handheld devices to professional devices with many features. Most auto parts stores will also provide this service if you purchase a code reader from them.