C drive not accessible

[himanta]

I am using dell inspiron 3543 ( i5 5th gen , 8GB RAM 1TB HDD,intel HD graphics) running windows 8.1 . One day i some how changed my 'C' drive sharing setting to "deny all" so that my brother can't delete my games ,but i have no idea that now i can't revert the settings because menu is not opening since 'C' drive is not accessible , i tried reseting(by rebooting and pressing F8...so on) but that option is also not showing ,even cmd(admin) is not opening , there is a problem in boot sector , there is no hardware damage, i searched youtube and microsoft forum but can't get it solve, please guide me how to fix it.

[tikker]

You should have just denied access to your brother's account. By denying access to everyone, you've probably locked yourself out as well. You  probably weren't the original owner of the drive then.

Try changing permission under right click>properties>security or logging in as administrator and see if you can claim ownership that way.