Download EQS4WIN Lite Version

EQS4WIN Lite is a fully functional version, apart from problem size and input/output restrictions. It contains many example problem files illustrating its use for larger problems.
EQS4WIN runs on WIN95/98/NT and 3.1
(It also runs under SoftWindows on a Power Macintosh; disable the 80487 emulation.)

A complete installation requires the files SETUPEQS.EXE and VBRUN300.EXE. They can be retrieved by clicking on the indicated buttons below. (If you already have VBRUN300.DLL on your system, it need not be downloaded. You can alternatively obtain this file from elsewhere.)
Install EQS4WIN by running the program SETUPEQS.EXE from Windows Explorer or the 3.x File Manager. It requires about 3M disk space when fully installed. (VBRUN300.EXE is installed using the same procedure.)



Note that the Lite Version includes only Version 1 features. The Standard Version must be purchased to use the expanded JANAF-compatible database available in Version 2, and to enable use of the TRC supplementary organic species database.

To upgrade the EQS4WIN Help File only, download and execute the file EQSHLP.EXE. (The latest Help File version is 1.1.2, Feb. 6/98. The Help File version number appears at the bottom of the Table of Contents Help Topic, accessed from the Help button on the opening screen of EQS4WIN.) Run EQSHLP.EXE. and install the Help File in the directory that contains EQS4WIN.EXE.


You may alternatively download the files via anonymous ftp from our site at We understand that this can be much faster from some locations (e.g. Europe). After you login, go to the directory usr/mathtrek, then get the files. If you prefer to receive a copy by regular mail, please submit a request to, accompanied by $US10 payment, refundable against the upgrade purchase.

If there are any problems with the downloading or the installation processs, contact Mathtrek Support.