I just installed Ubuntu 12.10 on my Windows XP SP3 GR desktop using ubuntu dvd from iso file. Operatings systems are in diferent hard disks. After the install I did not get the option of choosing OS and directly went to Windows XP. I think it has something to do with GRUB, but I'm not really sure. Please help. Thank's
Grub2 probably got installed on the Ubuntu hard drive, while the machine is booting off the First (Windows) drive. Change the boot order in BIOS to boot off the second hard drive first and you should either get a boot menu with both OS's listed, or it may boot directly into Ubuntu.
If it boots directly into Ubuntu then you should update the grub boot menu with the command