If you have an old computer that has not been updated for last several years you need to check for the following.
The Medical Tests Analyzer is written for .NET Framework 2.0. Before launch Medical Tests Analyzer setup package you need to install on your computer the .NET Framework redistributable package NetFx64.exe. It is available as a stand-alone executable file. As a result of downloading you will receive a file named NetFx64.exe. Use NetFx64.exe for deployment purposes.

Visit Microsoft Download center

Download NetFx64.exe

Before download NetFx64.exe please read .NET 2.0 Framework Redistributable End-User License Agreement
Note that administrator privileges are required to install NetFx64.exe. If you have previously installed the .NET 2.0 Framework SDK or Microsoft Visual Studio 2005, you do not need to install NetFx64.exe.

How to detect .NET 2.0 framework installed or not?
You need the MS .NET 2.0 framework to run this software. The .NET 2.0 framework is a foundation that a wide variety of software can build on without repeating basic information, and vertical apps can be very small in size. The .NET 2.0 should not hurt your PC in any way. Here is how to check if you have .Net, and what version:
Go to "Control Panel" of your PC. Then select "Add or Remove Programs" and see if it is listed there. If it is - you have it, if it is not - you need to install it.
If there is the following record presented in the Programs list:

Microsoft .NET Framework 2.0

you do not need to install .NET 2.0 Framework. Also if you have latest versions of .NET listed (3.5 or 4.0) you do not need to install. Otherwise you need to download and install .NET 2.0 Framework.