just run the mbr. its pretty easy
1.Restore Windows XP MBR
To start the computer and use the Recovery Console to replace the MBR
1.Insert the Windows XP Professional Setup CD-ROM into the CD-ROM drive.
2.Restart the computer. If prompted to press a key to start the computer from the CD-ROM, press the appropriate key.
3.When the text-based part of Setup begins, follow the prompts. Press the R key to repair a Windows XP Professional installation.
4.If you are repairing a system that has more than one operating system installed, from the Recovery Console choose the Windows XP Professional installation that you need to repair.
Note: If you press ENTER without typing a number, the Recovery Console quits and restarts the computer. The Recovery Console might also show valid installations of Windows NT 4.0. However, the results of attempting to access a Windows NT 4.0 installation can be unpredictable.
5.When prompted, type the Administrator password. If you do not have the correct password, or if the security database for the installation of Windows XP Professional you are attempting to access is corrupted, Recovery Console does not allow access to the local disks and you cannot repair the MBR.
6.To replace the MBR, at the Recovery Console command prompt, type:
fixmbr
Verify if you want to proceed. Depending upon the location and the cause of the corruption within the damaged MBR, this operation can cause the data on the hard disk to become inaccessible. Press the Y key to proceed, or press the N key to cancel.