Thank you very much for your interest. Actually, I solved the problem meanwhile using a third party uninstall program, and it looks the issue has been solved, and I see no sign of Micro Focus Visual Cobol in Visual Studio which starts normally.
My Micro Focus Cobol version is 2.2 and Visual Studio 2010 Ultimate.
Now, I am afraid to reinstall and retry Micro Focus Cobol.
Regards.