Basically NO, you can work without the HDD installed at all if you want, just works like an ordinary Eurovox. Couple of threads re- the EV PVR >>>> http://forums.afterdawn.com/thread_view.cfm/675493 http://forums.afterdawn.com/thread_view.cfm/707997#4307030 http://forums.afterdawn.com/thread_view.cfm/708447#4309316