windows me

I am trying to fix my mother in laws dell, which people had just sabotaged.  My plan was to remove me and install xp, but she wanted her pictures saved.  A friend told me to just install xp over me, and it would not delete those type of files.  So I did;  Xp started to install, then stopped and said something about microsoft not supporting upgrading me to xp.  Now I cannot access either operating system.  Any ideas?