Following a fresh install of 12.04 on a dual HDD dual boot system first boot brought up Grub Rescue.

I installed Boot Repair in a live CD and ran the recommended repair. Boot Repair indicated a successful repair.

Upon reboot there is no entry for Win XP.

Gparted shows sda as full as it was before installing 12.04. Nautilus shows Win XP files intact.

I don't think this is a hardware problem. This dual HDD, dual boot system has successfully booted grub under 10.10, 10.04 and 11.10.

Boot Repair produced the URL