On Windows XP, browse to C:\Documents and Settings\All Users\Application Data\AB SCIEX\MPX Driver\Log\
On Windows 7, browse to C:\Program Data\AB SCIEX\MPX Driver\Log\
For MPX1.1: Browse to C:\Program Files\AB SCIEX\MPX Driver\Bin\log
For MPX1.0: Browse to C:\Program Files\Applied Biosystems MDS Sciex\MPX Driver\Bin\log\
*For those using versions of MPX Driver lower than 1.2.1, please upgrade immediately to the latest version, 1.2.1. This version contains a critical fix. Please read the release notes for MPX Driver 1.2.1 HotFix to February 2016 for more information.