will take care next time.But may I know the reason. The issue is not much about the software (a simple disk editor would do) but rather about finding out what actually happened. The MBR holds 4 partition slots. From what you report, you had three of them taken by the original install and the fourth one by the extended partition that contains the logical volume on which Windows 8 was later installed. The idea was to set the BIOS to permanently have the boot order as: CD first USB second Internal hard disk third then boot from the cd with the disk ALREADY connected (and needing NOT to press any key to select anything during boot). There is NO way on earth (if there is such a setting as Boot order in the BIOS and if the CD/DVD is actually bootable) that your laptop should boot to anything different from the CD/DVD. When you connect the hard disk to your desktop, you don't want to check if actual volumes are mounted in Explorer, you want to check if the added disk is found in Disk Management. If it is, use Hdhacker (or a disk editor) to get a backup of the MBR of that disk (first sector of the \\.\PhysicalDrive). http://dimio.altervista.org/eng/ Compress the backup in a .zip file and attach the .zip to your next post or upload it on some free hosting site and post a link, and' I'll have a look at it. jaclaz That is the case. the HD is neither mounted in explorer nor in the Disk Management.What can be the problem if I am not able to see the HD in Disk Management but able to see it while I boot from a bootable rescue CD.