To this you need administrative rights on that system
Select Start –> Run and type gpedit.msc ( Will open group policy editor)
On the left side, expand computer configuration–>windows settings–>security settings–>Local Policies–>select security options
On the right side, double click on Interactive login Do not require Ctl+Alt+Del. And select option “Disabled”. Press OK. And close the group policy editor window.
Again Select Start –> Run and type gpupdate to update the group policy.
Open Control Pannel and double click on User accounts. Select Change the way user log on or log off. Uncheck on Use the welcome screen.
Now you log off and log in again it will ask you to press Ctl+Alt+Del to login.
Please go through the link: How to enable or disable the CTRL+ALT+DELETE sequence for logging on to Windows XP, to Windows Vista and to Windows 7.
Hope this will work for you.