Dell Dimension 4550 running XP

I know I have to take this computer with old OS out of service, but I wanted to know if this is a good candidate for ubuntu or a NAS server or media server. It runs well and has maximum RAM. It does have SATA.

Are people using this as a movie server in their homes? Can this be a file repository and then automatically sync with the cloud to backup files? I have a router that would allow me to access remotely, but thought if its mirrored in the cloud I could access files from my onedrive. I am also considering moving to google doc, or amazon or some other cloud server for my files, but I thought if I kept syncronized files on my home network it would speed things up and reduce bandwidth.

Thanks for yout help in advance.