crashedcomputer

basically they sent me a cd with an updated version of windows XP which i downloaded onto my laptop. It downloaded itself on top of my old version and therefore I was unable to access any of my old files. I'll try and find this folder, I think I might have seen it before but I couldn't access it

I recently rang Dell to help me with a problem i've since sorted out. They obviously didn't understand properly, and sent me an updated version of my XP system. I downloaded it, and it just installed itself on top of the system I already have. now I can't access any of my old stuff but it still takes up all the hard drive space. Does anyone know how I can re-access the old system on my computer? many thanks.