how to install debian onto iso file ?

[Jabka Atu]

Hello ..
i need to install my os onto some type of file (i guess iso be best but you know best) .
the reason is that i can't change any thing on the pc (it's aint my laptop) but i can create as much files as big as i want .
so i thout that  i could create an iso on its ntfs harddrive and some how install on it debian and install lilo on floppy,or cd.

any way how can i do it ? .
Thnx in Advance