Installation problem of Studio 2019, Microsoft .NET Frameworkalready installed

Hi all,

I am running Windows 7 Pro. I have  SDL Tradios Studio 2015 installed on my PC.

I want to install 2019. Of course, I was running into the problem with the Microsoft .NET Framework. 

I installed it offline. And received the error message that it is already installed.

But Studio 2019 can still not be installed.

Anything helps.

Thanks,

Katharina