It comes with KDE 3.5.8 and Konqueror browser and a few other basic apps. Download size is 297 MB.
XP fits on a 700MB disk. Its final install size is 1.5GB or something.
Sabayon's disk is 4.5GB or so. Its final install size is 12GB.
Ubuntu fits on a 700MB disk. Its final install size is around 3-5GB, I think.
The Arch Linux download is 140MB. Its final install size is ~500MB. And this is without a GUI or anything. I don't see how it's possible that you got a PCLOS install, including a GUI, under 1GB. If the minimalist Arch core is 500MB upon install and KDE itself is over a GB... I don't know how you got under 1GB.