PicoQuant GmbH has introduced updated data acquisition software for its PicoHarp 300 time-correlated single-photon-counting system. Version 2.2 provides driver support for the 64-bit versions of Windows Vista. It also supports control for further monochromator models, permitting the automated recording of time-resolved emission spectra. Time spans in time-tagged mode are virtually unlimited if software processing is done in 64-bit numbers. The software is free to all owners of the PicoHarp 300.