You can Restrict any user to access task manager in windows XP , Windows 7 and Vista . Windows administrator can restrict any user to prevent to close running program .
1. Click on Start button then type taskmgr , then Right-click on taskmgr under programs and then Click on Properties .
2. On the Taskmgr properties windows Click on Security tab, and then Click on Edit .
3. Now Click on Add to add User name and on the next windows Click on Advance .
4. Now Click on Find Now , then Select User (com-networks) which you want to restrict in Search result and then Click on OK and again click on Ok .
5. Now Select User (Computer networking ) which you want to Restrict then find Read & Executeand Read then Click on Deny check box . and then Click on Apply .
6. Now Click on OK and Ok and again Click on Ok .