I'm learning how to work with radare2 tool. While I am stepping through the program (on windows7) radare2 prints some lines which can be seen on the picture. It seems to me as if the tracing is enabled but in configuration variables tracing is disabled. I would like to turn off this printing but don't know how.
You're using an outdated version of radare2. The output you're seeing was removed from the codebase yesterday:
If you update to the latest version then that output will disappear.