NT Check/Install Microsoft .NET Version 3.5 or >
Microsoft .NET Framework 3.5 or higher must be installed before installing NinjaTrader. To check your current version of .NET Framework, follow the link below and download the .NET Version Detector XI.
.NET Version Detector XI Download
Once download, open the .zip file and run the .exe file. The program will look like the screen shot below.

If you already have Microsoft .NET Framework 3.5 installed, it will display 3.5 in green. If it is red, you must install version 3.5 from the link below.