hpztsb04.exe - (1) Ghostscript device driver for printers understanding Hewlett-Packard's Printer Command Language - see here for more info or (2) Creates 1 or all 3 icons on taskbar. The 1st one has a yellow border around it warning that ink is low on the printer. The 2nd one is HP Device Detection Software and the 3rd one is about a card being inserted into the Hp printer