Normally, there are solutions available out there to restore grub or install grub provided that linux in installed first. How can I install grub while not having any partition which has an installed linux operating system.
Is it even possible to install GRUB like I want?
Boot from a Linux LiveCD which contains the Grub package.
Google suggests that Ubuntu's does and also points towards Super Grub Disk.
You might want to include more details about what you're trying to accomplish though. Do you only want to install an MBR in order to boot a non-Linux operating system?
Clicky for instructions.
Since Grub is a bootloader, and allows you to specify how one or more partitions may be used to boot a computer, it is normally installed after an operating system is present on one of the partitions.
There wouldn't be much point in installing Grub first — what would you tell it to do if there are no partitions (with operating systems) to boot from?