If the download is a compressed folder, extract all files to your desktop.
If you are using a QuantStudio 6 or 7 Pro system, you may require the newer "Design and Analysis 2.x" desktop software instead. Quantstudio Design And Analysis Software V1.5.1 Download
Guide to Downloading and Installing QuantStudio Design and Analysis Software v1.5.1 If the download is a compressed folder, extract