> <https://frame.neptun.bme.hu/hallgatoi/login.aspx>
> 
> However, even if I give the necessary
> login/password, only this page is downloaded,

Since that page contains a log in form, you must use the capture method, not
the U:P@url. <http://httrack.kauler.com/help/Authentication>
But since the login requires httpS it can't be done in HTTrack.