It is fairly common for computers to be running with old chipset drivers or to use the basic default drivers built into Windows.If you're having any kind of stability problems with your motherboard then it's a good idea to install the latest chipset drivers.Most chipset drivers come as a single unified software package which contains the various drivers for both chips.
You don't need to know the name of your southbridge to find it.
You can usually just ignore the name of your southbridge when it comes to installing your chipset drivers unless you have one of those rare motherboards which has one brand of northbridge and another brand of southbridge.
The most important of these chips are called the motherboard chipset.
The chipset has a driver which can affect the speed and stability of many of the devices built into your motherboard.
But a few motherboards use northbridge and southbridge chips from different manufacturers in which case you need to load the drivers for each chip separately.
When someone says that their motherboard uses the ABC chipset, they mean that their northbridge is ABC. Even though it's not strictly correct, you'll see the terms "northbridge" and "chipset" used interchangeably in many programs and websites.
They just use the name of the northbridge (the main chip) and ignore the southbridge (the support chip).
In most cases you find chipset drivers only by searching for a package which matches the name of your northbridge.
AGP slots are especially susceptible to flakiness caused by old chipset drivers.