A method and system for testing newly installed or recently upgraded software is presented. All software installation activities are tracked and logged. New and upgrade software is isolated, either physically or logically, and tested using diagnostic software. If the new/upgrade isolated software passes the testing by the diagnostic software, then it is allowed to operate in the presence of other previously installed software. If an error occurs during an execution of the new/upgrade software, either while isolated or in the presence of previously loaded software, a log of other concurrently running software is reviewed to determine a likely software incompatibility with the new/upgrade software.