You may receive the install error ID 1203 when you purchase Windows Live OneCare, install the free trial version, reinstall it, or install it to a second computer. This error occurs under any of the following conditions:
To install Windows Live OneCare, you must be running the US English version of Microsoft Windows XP Service Pack 2. If you are running another version of Microsoft Windows XP, you will receive a message that says the service is not available and you will be unable to install Windows Live OneCare.
If you are upgrading Windows Live OneCare from the free trial version or you are installing Windows Live OneCare on to a second computer, you must use the same Windows Live ID that you originally used.