These live discs never seem to work right. Ubuntu loads, but it's impossible (i.e. it won't work no mater what I try) to install Flash, which means I can't run things like virus online scans or updates. The UBCD for Windows is also a major PITA. It took me days to figure out why it wouldn't compile, and the only way it would finally compile is if I disabled a number of features (still no reason why those features caused any problems). After that, I found out that there's no way to install or use Flash, or even install any programs like virus scanners, OR install updates for a virus scanner that's already there. I was able to copy files off of the computer, but not save the computer, which should have been possible. These boot CD's are essentially worthless until these problems are fixed.
I just pulled a bunch of files off of a very sick hard drive that wasn't even letting windows load using whatever the newest Ubuntu is. I also installed flash while doing so, so I'm not sure why you're saying installing flash isn't possible - it is. Obviously it's gone when you reboot, but installing it isn't that difficult. I don't remember specific steps, but I don't remember it being other than expected. I imagine I just went to the package managed and told it to install flash or just installed it using the normal installer linked from a webpage that used flash.