It's a 100+ hotfix pack of many of the Windows XP SP3 fixes up for download.
These are fixes that you would have to call Microsoft and get through their support center.
This download may include additional applications bundled with the software's installer file. Third-party applications bundled with this download may record your surfing habits, deliver advertising, collect private information, or modify your system settings. Pay close attention to the end user license agreement and installation options.
You are advised to run Ad-Aware or similar programs after installing this product.