at the time of Login Button Click :
1- Check the user type and save in session e.g.
if(UserType == "Student" )
{ Session["Prefix"] = "stud" }
else {Session["Prefix"] = "admin"}
then at those pages where you want to disable , on their page_load do this :
if(Session["Prefix"].ToString().Trim() == "stud") { LoginPanel.Enabled = false; }