Uninstalled GRUB, need it back
 

I recently re-installed Windows XP, but ended up uninstalling GRUB. Is there a way to reinstall it from Windows XP?

No, there isn't. Windows doesn't believe in playing well with other operating systems.

When you re-installed xp, the MBR (Master Boot Record) was over-written with the xp bootloader. Your Linux is safe and secure; just not bootable.

Insert the first cd of the Mandriva installation set, and choose to boot from hard disk. It will detect itself on hard disk. Then you must go through the grub setup procedure.

If you are not familiar with that procedure, go to the Gnu website and download the grub manual while running xp. Study it, take notes; it only requires two or three steps to re-write grub to the MBR.