How do I install GRUB to a USB drive using Windows Vista?

"Ultimately I used this video for guidance.

Basically, the goal is to install the grub4dos loader to the MBR of the usb drive and copy its program/configuration files to the drive's root. To do this, you download grub4dos (the program) and grubinst (a utility to add the program's loader to a MBR).

Grubinst has 2 clients, a gui and a command-line utility. The video leverages the gui. It didn't work correctly for me - yelling that there was something wrong with my drive's partition table. Running the command line client worked though. If you run into the same problem look at the readme for options and use the gui to grab the hd# of your usb drive.

I considered UNetbootin but I

didn't want a tool to do this for me (wanted more understanding)
wanted to add many bootables to the usb"

"You can refer to this article - it worked for me. Edit the menu.lst to suit your needs.

The OP wants to install GRUB through Windows, and only Windows.

Try WinGrub."