I downloaded Kali Linux to a bootable usb drive and booted it up on my PC. I chose the graphical install and installed it. At some point it told me that it's going to wipe my whole hard drive and for some reason I ignored that. After that I booted up my PC and all I got was a black screen. So I logged on to my roommates laptop and downloaded a tool called boot repair and copied it to the usb drive. Of course this overwrote the Kali Linux installation files, and booted it up on my pc. After it was finished I thought that it would just restore my windows 7, but after booting my pc up I found out that it restored the Kali Linux. Now when I try to log in using Kali Linux it wont let me in as root, I've tried the password that I used during the installation and "toor" but neither won't work. So how do I log in in this situation?