XP shuts down but computer will not turn off

I have a HP Pavilion a250n running with Windows XP. Something has went wrong in the system from past couple of days. Whenever I shut down the system, its display gets turned off but I still feel the vibration of hard disk and all other aspects in the cabinet. So I manually need to hold download power button for about 10 seconds and then turn it off completely.

I don’t think this could be any virus issue because I have fully updated Norton internet security which runs scan twice every day. So whats the problem ? Please help.

Just follow these steps, hopefully it will fix the problem.

• Go to Start > Run > type Regedit and hit Enter.
• Navigate to the following Registry Key:
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
• Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.
• Data Type: REG_DWORD [Dword Value] // Value Name: PowerdownAfterShutdown
• Setting for Value Data: [0 = Disabled / 1 = Enabled]
• Exit Registry and Reboot