Windows 7: Cannnot run .NET programs

I discovered that when I execute a .NET program, I get an message that the program stopped working. The details give "APPCRASH". I downloaded some .NET test programs and these also will not execute. It is the same for .NET2.0 as for .NET3.5. As with my previous OS WinXP I just had the idea to uninstall and install .NET. In the list of installed programs I found .NET3.5 and .NET2.0 and uninstalled them*.

After that I downloaded .NET2.0 and started the installation. I got an message that I need to "Turn windows features on or off". What? I looked on the internet and found that .NET3.5 and .NET2.0 are a part of Windows 7 and you cannot install them. I found the .NET3.5 entry in the Windows features and put a check mark to all the options. An installation started but after a while I got an error.

I looked on the internet and did an check of the system files with "sfc /scannow" command. It found files and repaired them. I also found an cleanup tool for .NET for Windows 7, and run it successfully.



But I cannot execute any .NET program. I cannot install .NET so what can I do?

*After learning that .NET is a part of Windows 7, I realized that this could not be possible. But I saw those entrys is the installed program list with my one eyes and uninstalled them and I got a message that the installation was successful. Maybe you just ignore this story, but I tell it to let know exactly what happened.

Do a Windows Update.

Anyone know about earlier versions of .net prior to 2.0? Can one install them? I have a few older apps that require an earlier version and will not run without it.