Chntpw

I have read on a thread somewhere that chntpw is located in /pentest/passwords/ but it's not on my machine, i am running a fresh install of Backtrack 5 x64.
When i run apt-get install chntpw it doesn't find it. I've ran an apt-get update, and when i run chntpw it says it's available via apt-get install chntpw but i must enable universe... So confused.

I have the same issue. I have Bt5 GNOME 32 bit on a flash drive. When i try to run it it says install it. When I look for the file I can see it but when I try to run the program it says install. I have reinstalled it many times. I dont know why it is not working.