I HOLD NO RESPONSIBILITY FOR WHAT MIGHT OCCUR TO YOUR SYSTEM OR DATA. THIS IS SIMPLY A REFERENCE* Boot up your computer using Microsoft Windows Seven Bootable disk. (Check your BIOS setup)
* When you see the 1st Windows Seven installation screen appear, please configure your 'language' preferences.
* When prompted, click 'Repair your computer'.
* Startup Repair will automatically detect a problem. When prompted, click 'Repair and restart', and then restart your computer from the Windows Seven bootable disk. If Startup Repair does not automatically detect a problem, continue to the next step.
* click 'Repair Your Computer'.
* Click Command Prompt from the System Recovery Options.
* BootRec.exe provides the following command-line options:
* /FixMbr. Re-writes the master boot record (MBR) of the system partition to start Windows Vista. This won’t overwrite the existing partition table.
* /FixBoot. Writes a boot sector onto the system partition to start Windows Vista.
* Type 'BootRec.exe /fixmbr' and press Enter.
* Congratulations! You're done.
EDIT-- A simpler way might just be to run the startup repair wizard altough that has never worked for me its a shot and every system is different