Hello here is how I did a frugal install without burning a CD,
I already had a frugal install /mnt/home/precise5.7.1frugal
I made a copy of this folder and inserted a # into the file name
So it looked like this /mnt/home/precise5.7#.1frugal
I opened the original folder /mnt/home/precise5.7.1frugal
And deleted the contents.
I mounted my iso image Browser puppy 501, and copied the contents
to the empty folder /mnt/home/precise5.7.1frugal.
UN-mounted the iso, and re-started the laptop.
At boot I chose precise5.7.1frugal
and Browser puppy booted up
I started the Browser puppy install wizard chose frugal install,
when the wizard asked CD or FILE I mounted the iso and copied
the contents to Root Downloads,
Back at the wizard I chose FILE and browsed to Root Downloads
clicked on the sfs and the install completed.
I copied the boot info to menu1st
title Puppy Linux 510 frugal in sda1 dir Browserpuppy501
find --set-root --ignore-floppies /Browserpuppy501/initrd.gz
kernel /Browserpuppy501/vmlinuz pmedia=atahd psubdir=Browserpuppy501 nosmp
Unmounted the iso, deleted the folder /mnt/home/precise5.7.1frugal
Renamed the folder /mnt/home/precise5.7#.1frugal back to its original name, I removed the #.
re-started the laptop, at boot chose Browserpuppy501.
this worked for me, I have seen other methods for doing this
but they are to difficult for me to follow.