Avtech 793 dvr freezes on password entry screen

The problem is that the dvr keeps freezing on the password entry screen and will not allow me to enter the menu.I am having to reboot the dvr in order to enter the password and enter the menu.The camera footage is not affected by this and after reebooting works fine untill the following day.I turn the moniter on and as soon as i touch the mouse the password screen pops up and freezes.I have already formatted the harddrive and reset to user defaults and this has seemed to make it happen more regular.I am not using the dvr online.Thanks to anyone who can help

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793 looks like ivs type.maybe you should upgrade the firmware

HI ,could you tell me what a firmware upgrade is and were i get it from.Thanks

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Sorry, re posted as i thought i put it in the wrong catagory.