> and view them all OFFLINE. Which (free) version will
> be more suitable for the purpose?
> Is it completely free? Can I save what I want on any
> files or folders or pen drive either during online
> or during offline viewing? How to do that? Can I
> make any password to HTTrack Wesite copier?  

Httrack is free.
The mirror contains only relative references, you can put them on pen drives
or cdroms
Httrack doesn't require a password but can pass your name/password to sites
that require log a in.

Has I have said previously the current version is broken many different ways. 
I recommend 3.32 <http://www.httrack.com/httrack-noinst-3.32.zip>