Take it you're going from MSN Messenger 7.5 to Windows Live?
Ah, nevermind. Seems there was a security hack that came out yesterday where someone could take control of your computer if you were running anything less than the latest version on Windows XP - unless you use an alternate MSN client like Trillian, Pidgin, Adium etc you're stuck with Windows Live 8.1 on Windows XP
http://en.wikipedia.org/wiki/Windows..._vulnerability
