STEP Tools packages are distributed as ZIP files or Microsoft MSI installers. On most versions of Windows, you should be able to double click on the MSI file and the installer will launch. However, you may occasionally encounter the following issues.
STEP-NC Machine and some other Windows applications use the Microsoft .NET Framework. When you run the tools, you may see a message if your computer does not have the correct .NET version. You can download the latest from Microsoft below:
Sometimes a Windows installer dialog will repeatedly show this message and never seem to finish whatever it calculations it is doing. Solve this by right clicking on your "C:\" drive, select "Properties", and then run "Disk Cleanup". The problem is caused by large numbers of temp files or Recycle Bin files. Windows is examining all of them to figure out what it can remove if it needs extra space, even if you have hundreds of free gigabytes.