No login password EVER

Hi all, new here but id say im a 8 out of ten with win7 issues, BUT
and ive not come accross this before, ....ive just unlocked a dell whos owner is a 19yr old " educationally retarded teen".. However, he does have the where with all to play with some settings, particularly PASSWORD".
So what im looking for is a way to PREVENT a login/welcome password "EVER" being set...( i dont think hes up to accessing the bios)
i could pop down his dads and unlock the lappy every time he sets a password and forgets it, but if i can find a way to prevent a password being set in the first place, would save me a lot of time. (his father is a bit technophobic so no good giving him a usb "key/unlocker boot usb" and explaining boot sequence etc)
Anyone any ideas ?
thanks in advance
nigel

Hi Brink, just trying to automate as much as poss on his lappy but your first suggestion looks good so long as it will allow me to NOT to put any password in, ie blank... I dont know the lad but from what i can tell, he, or others know enough to upset loggin in.... I didnt want to reformat the lap as it was/ is working as best as he is able to use it, but the bottom line is stopping any further setting messing. Ive setup all he needs so far AVG,Spybot etc, and will set them to run at boot, i doubt very much if it will occur to him to run any "houskeeping" so ill set it up. Ive also put "Logmein" on so i can access the lappy in future, so long as he doesnt mess up his internet. Its a favour for my pet mechanic who works on my car, so id like to get it all running without much fuss, and of course, as a final solution ill be doing a Reflect backup which ill keep on one of my drives (no good for remote, but at least i can get it back to a running machine with ease).
Still got some stuff installing so ill try Prevent or allow when done. Hope your around in 30 mins or so.
nigel

Failed on option 1,
"this computer is running Windows 7 Home Premium.This snapin may not be used with this version Bla bla bla.

Dont forget, i dont want to stop him changing a password, i want no password at all and prevent him from applying one. Off to next option "elevated command prompt"

Failed on option 2, no local users and groups in lhs pane of Computer Management (local)