Hi,
I have installed fedora in a win8 machine with secureboot on. Since(idiot me), I have forgot to disable fastboot option of win8, the boot partition is messed up.
there is no boot option to boot win8; though fedora is working fine.
I do not have a win8 recovery disk; but I can see the win8 partition from fedora (though I cant mount it).
Is there any way I can recover win8 without buying there installation medium?

kindly help.

Possible, check the neosmart site below. The site below has a download for a Recovery disk for windows 8. It used to be free but due to licensing restrictions imposed on neosmart, they must now charge. Never had to use this myself, but I've read numerous reports that it works well. Read the details and get the correct link:

https://neosmart.net/blog/2009/windo...-repair-discs/

You might also do an online search for windows 8 recovery disk options. You may also be able to purchase a full installation CD if you bought the computer with windows 8 preinstalled, they are usually $15-$25USD.