Hello amethyst
shinobar's tools are important because they get beginners started with Puppy. When I started with Puppy 10 years ago I used grub4dosconfig. Fortunately I spotted the little checkbox for " show partitions" and was able to install grub4dos start properly, the IBM PC way, from the partition boot sector. Once you have a working Puppy, I don't think you need the installer again. It's easier to do it manually.
I think this commit from yaya in 2014 dealt with the issues of GPT and 64-bit ext4, but I haven't used either so I can't confirm that it works.
https://github.com/chenall/grub4dos/com ... 0fac75880d
Note: you would have to start G4D from the PBS for this to work: I don't think weee supports 64-bit