I have some bad sectors on the hard disk which is preventing me from loading windows OS.I presently have ubuntu OS on it but i need to change it to windows. How do i repair the bad sectors to be able to load my desire OS. Thanks

That problem is from HDD, It can be bad sector on MBR \ on line for boot record\. Change your hard disk , if it in warranty , will be well.

Sounds like your hard drive may have developed bad sectors preventing your OS from working properly.Also you may need to install a fresh OS once the sectors are repaired but usually not.Hard Drive Regenerator is a good software for regenerating bad sectors,if they are repairable that is.Either way it sounds like a failed or failing hard drive.

These sectors can be fixed.

1. For Windows
   • 1 Double-click on My Computer to open the My Computer window.
     
   • 2 Select the disk that you want to diagnose and repair.
     
   • 3 Choose Properties from the File menu. You should see the Properties window for the drive that you selected.
     
   • 4 Choose the Tools tab.
     
   • 5 Click the Check Now button under Error Checking Status.
     
   • 6 Depending on your version of Windows, choose either "Thorough" or "Scan for and Attempt Recovery of Bad Sectors."
     
   • 7 Click on Start.
     

Read more: How to Fix Bad Sectors on a Hard Disk ' eHow.com http://www.ehow.com/how_113636_fix-sectors-hardfix-sectors-hard.html#ixzz1PeS42ET5

You may need to be logged on as an administrator to do this

Open the my computer window, and right click on the drive in question and select properties from the menu that appears. A window with several tabs will appear, the one we want is labelled tools.
From the tools tab, click check disk for errors ( the first option, at the top ), you will be presented with a box with a few options, (fix file system errors, and scan for bad sectors) make sure both boxes are checked, and click ok, the machine will ask if it is ok to reboot, allow it to do so.
The self check may take a few minutes to half an hour or more to complete, then windows will load as usual.

This should fix your problem :)

I would recommend using a boot disk and run chkdsk (windows boot disk) or fsck (linux) This will help fix bad sectors if you use the correct options. USe the "/?" in windows for help and "man fsck" in linux.

Good luck and let me know how it goes.
Joe

first try booting in safe mode

last if nothing seems to be working then just reinstall the windows as it seems to be that there is some preoblem with OS.

Have your disk replaced with new one..It might have developed lot of bad sectors,.,

Bad sectors on a hard disk is an every day thing, the hard drive keeps a bunch of spare sectors and a table to reroute bad sectors to the backups. This warning basically means that you are out of backups, and now you may start losing real data if you do not change the hard disk.

define "dead" is it merely a failed partition, or bad sectors on the platter itself? if its bad sectors in some cases you can send it away and the will change the steel disk itself, but usually it costs quite a bit to have done, if its just a dead partition, you could plug it into a system as a slave, boot to a windows XP disk, destroy the damaged partition and simply lay a new one..