CP Technologies has been a long-time provider of ruggedised computer equipment for military and industrial applications for over 18 years. Over the years, some aspects of designing rugged computers using COTS components have remained the same, while other areas have greatly changed. This paper discusses how CP Technologies designs and manufactures its ruggedised systems for harsh environment applications. Below we cover the following topics: shock and vibration, temperature, protection from dirt and dust, and EMI/RFI shielding as it relates to our product offerings.