Popped WHAT??

If popped caps makes you think of popped collars, the thing to keep in mind is that while popped capacitors are bad, they're not as bad as popped collars.

What capacitors do:

PC's use what are known as electrolytic capacitors, and are typically a little can that acts as a filter (in the case of a power supply, smoothing out the rectified AC line voltage that's then switched and stepped down to yield the various system voltage rails). If so, without that cap, you'd be introducing line harmonics and ripples from rectification into your PSU and the rest of your computer and potentially damage other components (or at least stop them temporarily from working correctly per design). Caps on the motherboard likewise act as filters and timing agents, providing smooth power and discharging as needed for certain circuits.

What are popped caps:

That being said, popped caps can lead to a need to upgrade or replace your computer. Capacitors are designed to be power filters and timing mechanism in all sorts of electronics, and especially in PC's. Generally speaking, you won't find this problem in a new PC, it happens as the electronics are exposed to heat over a long period of time. Most people notice a problem with their computer, locking up, or giving unusual errors, and they seem to be after the PC has been on for a while, and not following any given pattern, happening randomly. Sometimes it's so bad, that the system simply refuses to turn on.

Identify popped caps:

The quickest way to find out if popped capacitors are an issue is to open the case and visually check the little cans all over the motherboard and add-in cards. If you see signs of them being cracked, split, bulging, or leaking, it is time to get a new Motherboard (upgrading at the same time) or getting a new PC altogether. Here are two pics showing typical popped caps.

We don't recommend replacing caps on motherboards.

Damaged capacitors don't filter properly and give irregular timing spikes which causes not only problems as a PC operates, but can also cause damage to the digital circuits that they are used to regulate.