I was searching for a topic that a user wrote about making the private key of a paper wallet offline.
He was recomended to make it on a new installed OS or with a live CD.
I want to ask if is the same secure to make it in a OS which is running in a vitrual machine like VMware?
And second question is : after i make the private key i have to connect the program in the internet so it gives me the Public Address?
The public address is generated directly from the private key - you don't need to be online.
Just download it first from somewhere you trust (ie github
https://github.com/pointbiz/bitaddress.org - download the zip file) and put it on a usb stick (it's just javascript that runs in a browser - just open index.html). Play around with it in Windows so you understand how it works.
I can see no problem with using a Virtual Machine - but it's just as easy to put Ubuntu onto a bootable USB stick. Just make sure you are disconnected physically from the internet.