Один из вариантов проблемы и решения
http://support.microsoft.com/kb/839017/ru
Второй вариант
http://www.answersthatwork.com/Tasklist_pages/tasklist_h.htm
In most cases this task terminates once the Windows Update terminates and/or you exit the Windows XP Help. It has been known, however, not to terminate itself and instead to run away with CPU usage, up to 90%, with the obvious impact on the PC’s performance. If this happens regularly create a DWORD entry called Headlines and give it the value of 0, for the following Registry Key HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ PCHealth \ HelpSvc \ (only advanced users should attempt this). This disables the Headlines feature which simply means that your Help and Support Center headlines are never updated.
