Hi, thanks for using Justanswer.com I am Cris. If the partition is destroyed you cannot repair it.
Instead you can order the Recovery Media for your computer and reinstall from the disc. Here is the link you will need to order them.
Let me know if you have any further questions. Please take the time to rate my service at the top and submit.
I wanted to follow back up with you and see if you had any further questions? Please let me know.
Please also take the time to rate my service at the top and submit.