I was able to install and start it up on XP. But it wants a Java upgrade that is not available for XP. The instruction call out for "MainMenu.exe" to be copied but does not give the directory path. The e-mail identified: C:\Program Files (x86)\Toyota Diagnostics\Techstream\bin Regardless, it runs and communicates with the OBD. I'll try it on our 2017 Prius Prime and later today, the 03 Prius. I've ordered an OEM version of Windows 7, 32-bit. I'll load it in another virtual PC and hopefully get the Java download to work. Bob Wilson