The Quadstar(tm) mass spectrometer control software has now been released in a MS Windows(tm) XP/2000 version. It can be used with all Pfeiffer Vacuum mass spectrometers. A on-screen help function is now included, and the 32-bit software can be used to setup operating parameters, collect partial pressure data and perform analysis. It enables the tuning of ion source current and voltages as well as total pressure measurement and leak detection modes.