What is the password for the Linux Bood USB ?

I need to change some files while booted via the linux usb key. (version 17 I think I have )
I press Alt F1 and get a screen for Ubuntu. But I need a login name and password. I tried the default Ubuntu password which I think is ubuntu/ubuntu but this did not work.

I have contacted support but this is spotty, can anybody tell me what this is?

Or is there another way to get at configuration files and edit text in them.

Thanks.

Ok Im going to post again. As my last post didnt seem ?? to post The password is root/root press Alt F1-F6 in backup version 17.