Okay sorta only days old to the whole Linux world so this may be an extremely noob question.

I am trying to retrieve the chntpw package when using the ubuntu 12.04 booted from a USB. When I plug in the command "sudo apt-get install chntpw" I get the error "E: Unable to locate package chntpw".

I've tried to use the command "sudo apt-get update". I've downloaded other packages and they downloaded just fine. (the package I used for a test was nmap). I've even booted my laptop normally on Win7 used ubuntu through the virtual box program and it downloaded the chntpw package without problems.

Not sure what I'm doing wrong. Any ideas???