Best Solution =========== Durai>> I realised my system was affected by Serial99 virus with in an hour, because it disables the system shutdown and task manager, Run etc. So what I did is I just restore the system to the previous system restore point. This is working very well and itsvery superb!! I'm happy now To do this, open windows system restore option Start>>Programs>>Accessories>>System Tools>>System Restore. But one important thing, already you should have enabled the system restore in Windows XP, otherwise thisway is not possible!!!! How to check whether is it enabled or not, Right Click My computer and click properties, which opens "System Properties". Choose "System Restore" Tab. In that "Turn off system resource" should NOT be checked. Happy anti-hacking!!! One more Note: I have chose the restore point of the previous week on which my system is not affected by virus. Otherwise restoring the point of day, where already system is affected is no use. (Moderator edit: Posts merged. Please use the edit button, rather than replying to your previous post where there are no other replies in between. If bumping the thread, please wait at least 24 hours for a reply.