For the ecomometric analysis of time series data, Microfit should be a valuable package. With its choice of data analysis options, this program is an aid to all those interested in the evaluation and design of advanced univariate and multivariate time series models. Microfit is an interactive, menu-driven program with facilities for estimating and testing equations, forecasting, data processing, file management, and graphic display. Version 4.0 builds on the success of its predecessors, but should now be easier to use in both its new Windows format and its original DOS environment. It is a resource for business, banking, teaching, and research. Systems requirements are: Windows/DOS: IBM AT or PS/2 (or full compatible) with 80486 or 80486SX processor. At least 8Mb of free RAM (Windows) or 4Mb free RAM (DOS). Maths co-processor is required with an 80486SX. DOS 3.0 or higher. At least 8Mb free hard-disk space (Windows) or 12Mb (DOS).