i av tried all initial suggestion including scanning for virus and malware.my system is cleaned now.i even run the reimage software to comfirm,any more sugestion

Hi, The Security Center service cannot be started due to virus destruction. Have you tried the repair for Windows? If not, you can go to following SkyDrive to load the registry and import it to check the result. http://cid-9fb18a384ebfc662.office.live.com/self.aspx/.Documents/wscsvc%5E564%5E6.zip Before importing it, please back up the following registry key first. Just find the key and right click it, choose export and save to desktop. [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\wscsvc] After importing the correct registry, please go to services Windows to check if Security Center starts properly. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

thanks to all who have contributed to my request, zhan tan reply was most helpful.thanks again.