my OS is xp. my PC is affected by virus so i format my HD and install XP with network cable disconnected so as not to affected by virus during the long-time installation. after the xp installation finished, the HD shld be "blank" except the xp system files. so i install the Norton anti-virus first with network disconnected. after the Norton installation, i have to run the Live!update virus definition, all these are OK. the problem is after the Live!update, the Norton will do full system scan and start auto-protection, at this time Norton is disabled, email scan, full system scan and auto-protection all are disabled. when i tried again, even if i click on the Norton icon, it doesnot make any sense. i use the symantec "fixWelth","fixblast",and Macfee "Stinger" scan my full system with network disconnected, some virus "Svchose.exe""welchia" are deleted, but the Norton anti-virus atill doesnot work and the "CPU usage" in "task manager" is 100%, someone says this is due to the duplication of SVchost.exe.Another more important is when i tried to run "regedit", the "regedit" window will close soon automatically before i take any measures. Can some one tell me what virus it is ,how to remove, and how to enable my Norton anti-virus ? thanks a lot!