Was given this link by AC support a while back and saved it - although I think I also had luck with just installing the AC with the version of make it possible for this computer to sync and bring back - full install.
http://support.microsoft.com/kb/260885I actually just took my Vista computer out and replaced it with 5$500 Windows XP home machines that work great as workstations. AC told me about this and I never had to use it, but error 429 was a common error.
