Instructions - installing PLD RescueCD on a USB drive.

First, download the latest version of PLD RescueCD and usb.zip.

You should now have a files: 
http://rescuecd.pld-linux.org/download/PLDRescueCD-2.00/x86{,_64}/rescue.iso
http://rescuecd.pld-linux.org/download/PLDRescueCD-2.00/usb.zip

where 2.00 is the current version.

Unzip usb.zip to your USB drive you can do this in Linux using
the unzip command, or using Winzip in Windows.

From rescue.iso you must copy ONLY the following files to the / on USB drive:
    boot/isolinux/initrd.ide
    boot/isolinux/vmlinuz
    boot/isolinux/memtest
    rescue.cpi

Then run syslinux, which will install the bootloader needed for
rescue to be able to boot from the USB drive. Syslinux can be 
downloaded from kernel.org, and you can find out more about it
at http://syslinux.zytor.com. Under Linux, you would type:
    syslinux /dev/sda1
if your USB drive is usually found at /dev/sda1, 
and in Windows type:
    syslinux.exe E:
if your USB drive is found at E:.

Finally the directory listing of the USB drive could look somewhat like this:

drwxr-xr-x  2 areq users      135 Jul 21 16:06 .
drwxr-xr-x  9 areq root      4096 Jul 21 12:55 ..
-rw-r--r--  1 areq users     1559 Jul 18 19:39 boot.msg
-rw-r--r--  1 areq users      962 Jul 17 23:17 help.msg
-rw-r--r--  1 areq users     8204 Jul 17 23:17 ldlinux.sys
-rw-r--r--  1 areq users   553984 Jul 18 17:14 initrd.ide
-rw-r--r--  1 areq users    81892 Jul 10 22:28 memtest
-rw-r--r--  1 areq users 51171328 Jul 18 10:44 rescue.cpi
-rw-r--r--  1 areq users     1055 Jul 21 13:22 syslinux.cfg
-rw-r--r--  1 areq users   873984 Jul 18 10:43 vmlinuz

That should make your USB drive bootable, and now you can run PLD RescueCD.