Well, you can follow this way to do that:
Try out following things to tackle with this problem-
•If the problem is caused by BIOS problems, update your system BIOS.
•Check out the hard drive settings of your computer in CMOS. Verify that the drive is detected in CMOS. Try changing “Access Mode” of your hard drive to either LBA (Logical Block Addressing) or Large.
•If damaged or missing partitions are causing the problem, delete and recreate them.
Although, the above methods may fix the issue, but also has a few drawbacks. Incorrect modification to BIOS and deletion of Windows partitions may cause serious data loss situations. In such circumstances, it becomes essential to use third-party hard disk recovery software free download to extract lost data from Windows hard disk.
The Disk Recovery applications are powerful enough to perform intensive scan of affected Windows hard drive and retrieve lost data. They have rich graphical user interface to enable recovery on your own. With read-only conduct, they perform safe recovery and preserves integrity of your data.
Stellar Phoenix Windows Data Recovery is the best ever made utility that ensures absolute recovery in all cases of Windows data loss. The software is usable with Microsoft Windows 7, Vista, 2003, XP, and 2000. It recovers lost FAT16, FAT32, VFAT, NTFS, and NTFS5 file system partitions and stored data.
The source:
http://hubpages.com/hub/How-To-Fix-Error-loading-operating-system-Error-in-Windows-XP Answered May, 21 2011