When I install Ubuntu 12.04 along side Windows XP, I encountered a choice for "Device for boot loader installation". I selected "Windows XP Professional" Now, when I select Windows XP from the grub, it appeares a black page and Windwos dosent boot. I tried Boot-Repair from Ubuntu but it dosent solve this problem. The only thing that helps me to boot Windwos XP is a Bootable CD of Windows. when I put this CD and boot from CD, it shows some options and when I select "Boot from Hard Drive" , my own Windows boots!

Here's is a snippet from the bootinfoscript report:

============================= Boot Info Summary: ===============================

 => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of 
    the same hard drive for core.img. core.img is at this location and looks 
    for (,msdos5)/boot/grub on this drive.

sda1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Grub2 (v1.99-2.00)
    Boot sector info:  Grub2 (v1.99-2.00) is installed in the boot sector of 
                       sda1 and looks at sector 525709174 of the same hard 
                       drive for core.img, but core.img can not be found at 
                       this location. No errors found in the Boot Parameter 
                       Block.
    Boot file info:      Grub2 (v1.97-1.98) in the file /mbr_backup.log looks 
                       at sector 1 of the same hard drive for core.img, but 
                       core.img can not be found at this location.
    Operating System:  Windows XP
    Boot files:        /boot.ini /ntldr /NTDETECT.COM