[newbie] Can't find KDE

[Juliana]

I installed mandrake in my computer and now i can't find any of the graphical intarfaces. I tried typing KDE and kde after loging in and the screen became black. maybe that's not the right command, then if it's not, what is it? Another thing i noticed is that the only folder under the user is one called /tmp. maybe that's the problem.. I don't know. i'm sure i choose all the graphical interfaces for installing.             What should I do?   Juliana