A HowStuffWorks reference on When to Use a Surge Protector,
this is a page from a list of pages on surge protection (move to the next page too).

This is my take on a surge impact to a home PC.

1. If you are lucky, only the PSU will be damaged

• after that, your motherboard regulators and graphics card can be killed
• beyond that your processor and other motherboard components may be damaged
  you can also loose your monitor power circuits on the way

A HowStuffWorks reference on When to Use a Surge Protector,
this is a page from a list of pages on surge protection (move to the next page too).

This is my take on a surge impact to a home PC.

1. If you are lucky, only the PSU will be damaged

• after that, your motherboard regulators and graphics card can be killed
• beyond that your processor and other motherboard components may be damaged
  you can also lose your monitor power circuits on the way