HOW TO FIX MBR ERROR IN WIN7?
How to Fix MBR Error in Windows 7
If you’re having boot problems on your Windows PC, it’s often helpful to
repair the MBR (Master Boot Record) to restore the Windows 7 boot
loader—and you can do it easily from the Windows installation disc.
This is generally most useful if you’ve broken something and there’s a boot loader error,
or if you have made the mistake of installing an older version of
Windows on the same PC that already has Windows 7 which wipes out the
boot loader.
Note: If your PC starts booting into Windows but fails, you should probably try using Safe Mode instead.
Boot From the Windows Install Disc
The first thing you’ll need to do is boot off the install disc, and then
click through until you see the “Repair your computer” link in the
lower left-hand corner.