Not sure how to hide a single task, but you can disable the task manager, so they cannot open it at all, heres how
Open My Computer > C: > Windows > System 32 > RegEdit
Expand the hive: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
Right click the right hand window, somewhere in the white area (you will probably have Disable Registry Tools already in there).
Create a new DWORD
key using the following
Then double click your new key and change the value to 1
Exit your registry and try opening task manager, it should be disabled, preventing users cancelling running services.
To enable the task manager again simply change the value of the new key to 0
Note: Take great care in editing the registry as its the heart of your computer, always double check your in the right place before changing things
Edited by Mark K, 23 November 2007 - 06:08 AM.