Security update for Windows XP KB2659262 repeatedly fails to install (error code 0xD000012F)

Hi Sangbin,

Have you made any changes to your computer recently?

I would suggest you to follow the steps and check if it helps.

Method 1: Perform a clean boot and then check if it helps.

How to configure Windows XP to start in a "clean boot" state

Note: Make sure to perform the steps under Steps to configure Windows to use a Normal startup state to boot your computer normally.

Method 2: Follow the link and run Microsoft Fix-it and then check if it helps.

Automatically diagnose and fix common problems with Windows Update

Method 3: Install updates manually and then check if it helps.

To install updates manually by follow the steps mentioned below.

a)      Go to http://www.microsoft.com/download/en/default.aspx

b)      Search for the updates using KB article number for the update.

c)       Download and install it. 

Method 4: Reset Windows update components and then check if it helps.

How do I reset Windows Update components?

To do so: Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

322756 (http://support.microsoft.com/kb/322756/ )

How to back up and restore the registry in Windows