I think I've managed to succesfully install puppy 4.0 to my laptop's HDD (no windows), and configured the GRUB properly, so I have (and can choose) the option to launch Puppy, however, it all goes OK, until it scans for serial peripherals and tells me I have a PS2 mouse and keyboard, then it seems t...

I had the same/similar issue. After choosing Xorg, it started but then failed (this is all on a DOS-ish screen (yeah, former/current Windows user too)), so I had to type something like 'xserverconfig' and choose the alternative (Xvesa?)