How to fix MBR in Windows 7

1. Start PC, Insert Windows 7 DVD and hit a key when asked to. You may have to change your boot order to boot from DVD!
2. Click on “Repair your computer“:

The installer will now search for Windows installations on your PC and list them all.
3.Select your Windows 7 installation and click on next.

4.Click on Command Prompt

5. Enter the following command on one line: bootrec.exe /fixmbr




/fixmbr
This will create a new Master Boot Record, but will not overwrite your exisiting partition table.
/fixboot
This will add a new boot sector. If you boot sector is damaged you might not be able to start your system.
/rebuildbcd
Scans your disk for Windows-7 compatible installations, needed to repair your Windows 7 installa