You didn't ask a question!!!
I'm guessing you'd like some steps....
- Download Fedora
- burn to CD (be sure to "burn from iso")
- Boot from the CD
- Tell the installer to take the partition where Xandros now is.
- Allow the installer to put the bootloader in the mbr***, It will automatically detect the Windows install and configure appropriately.
- Reboot
***Caution!!! Do this only if you have a Windows install disk--or some way of restoring the mbr if something goes wrong.
Better advice: NEVER buy a computer that does not include an install disk for the OS