You can use this ISO to create a Windows XP SP2 install disk for installing XP to a flash drive or memory stick.
Unfortunately the drive will only be bootable on the motherboard it was created on.
Using a flash drive with Mini ITX motherboard can make a very compact computer.
I generally prefer using Ubuntu to make a bootable flash drive however there are some places where only windows will work ie using S-video on some motherboards.
This is based on XP Pro Essential which passes WGA