This could be caused by conflicting software. If you have other antivirus or antispyware programs installed, uninstalling them should resolve the issue. If you have no conflicting software or uninstalling it does not resolve the issueplease contact support. How to reach support - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90Jim - MVP Windows Live - Forum Moderator - Live One Care - Live Mesh