I couldn’t access Advanced Boot Options from BIOS, so I used a windows installation disc as you said. From there, with F8 I entered the Adv.Boot Opt. but I don’t see the option “Repair your computer”.
I have:

Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt

Enable Boot Logging
Enable low-resolution video
Last know Good Configuration
Directory Services Restore Mode
Debugging Mode
Disable automatic restart on system failure
Disable driver signature enforcement

Start Windows Normally