I started CB with arguments -v --debug-log, and it worked! the output when loading headers is
"ClassBrowser::OnThreadEvent(): Updating class browser...
ClassBrowser::OnThreadEvent(): Class browser updated.
SystemHeadersThread: C:\MinGW\lib\gcc\mingw32\6.3.0\include\c++\ , 656
SystemHeadersThread: C:\MinGW\lib\gcc\mingw32\6.3.0\include\c++\mingw32\ , 23
SystemHeadersThread: C:\MinGW\lib\gcc\mingw32\6.3.0\include\c++\backward\ , 8
SystemHeadersThread: C:\MinGW\lib\gcc\mingw32\6.3.0\include\ , 90
SystemHeadersThread: C:\MinGW\include\ , 2346
SystemHeadersThread: C:\MinGW\lib\gcc\mingw32\6.3.0\include-fixed\ , 3
SystemHeadersThread: C:\MinGW\mingw32\include\ , 5
SystemHeadersThread: Total number of paths: 7"
and it resolved my problem because when I rebooted my CB, the suggestions were rights. Thank you for help!