Long story short, I had Ubuntu pre-installed on my PC. I wanted to replace it with Windows 7, and after a long laborious process, successfully booted up the Windows 7 ISO on my computer with a USB. However, all my partitions were deemed unable to install Windows. To make a long story short even shorter, I deleted some partitions, rebooted, and got stuck on an EFI shell screen. I then typed in the command, "exit", and now I'm stuck in Grub Rescue. I am tired, and I am desperate. Please help!