Will Ubuntu work if I install it offline?
Solution 1:
Yes it will work, however with some restrictions. For example there are "Must do" updates if you want to play MP3s or movie files etc. (Ubuntu Restricted Extras).
Also you need to install medabuntu libraries if you need to play DVDs. There are others but apart from these restrictions Ubuntu will work.
I had to to this once and was able to update everything at a later date
Solution 2:
As everybody say, you can install Ubuntu 12.04 offline but there will be a lots of packages, updates and softwares that you may need.
To solve this problem, you have different ways to install software and package in a computer without a Internet connection.
One option is Keryx, a portable package manager. Keryx offers to you a nice GUI making easy to use it. And, as if it were not possible to be better, it's open source!
How it works?
You download the package that you need in another computer with Internet connection and then install it in your computer offline.
You can download Keryx from their official website. This software support 32 & 64 bits architectures.
A screenshot:
Solution 3:
Absolutely, you just wont get the updates at the time of installation.
Solution 4:
You can install Ubuntu without an Internet connection.
From my experience it is not good idea to install Ubuntu offline, some third-party software needed to install from source or script which will cost you extra trips to get the missing packages.