Please help me, I realize this problem when I attempted to install an unknown program, which could be the virus. After I did a full system scan, the anti virus told that the virus has changed several settings. How can I fix this problem?

Hi Dough-Us, I suggest you first try a free online virus scan on the following site: http://safety.live.com For information about Security updates, visit the Microsoft Virus Solution and Security Center for resources and tools to keep your PC safe and healthy. If you are having issues with installing the update itself, visit Support for Microsoft Update for resources and tools to keep your PC updated with the latest updates. After removing those potential malware or virus, you can check the following thread for solution regarding Security Center issue: security center service will not start http://social.technet.microsoft.com/forums/en-US/itprovistasecurity/thread/c3e600fc-d3d7-4d8a-9bc4-c1eb0398664c/ Hope this helps! -------------------------------------------------------------------------------- Sean Zhu - MSFT

ok..... lets try this...open services,select security center and right click for its properties,logon as NT AUTHORITY\LocalService.no password required.now apply and start service. ok reply.