Patricia, do you mean that the virus and spyware protection in OneCare won't start?
If so, try this -
Virus and Spyware repair tool - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2667445&SiteID=2
If that doesn't work or you have a different OneCare problem, please contact OneCare support.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve