I have checked at crucial.com, and you can upgrade your memory on that D400 to 2GB. But still, from my experience, a 1.4Ghz 32-bit processor and 2GB of RAM is not going to do what you want on Linux Lite. LXLE is your better option, and as long as you're going to try its Live Media, I suggest you do it using their 14.04 series first. Their 32-bit download files aren't easy to find, so I'll private message you the *.torrent file.