Open gpedit.msc from either the Run prompt or from the Search box.

Under Local Computer Policy, go to <fc #6495ed>Computer Configuration</fc> → <fc #6495ed>Administrative Templates</fc> → <fc #6495ed>System</fc> → <fc #6495ed>Logon</fc>

Select the entry that says: <fc #6495ed>Hide entry points for Fast User Switching</fc>: Enable