It is possible to have two versions of GCC to coexist: the native windows MinGW version and the cygwin linux version? Things get problematic when on Cygwin the system tries to c
Having both of them installed causes no harm, its just like having 2 set of files on the disk. Apparently it doesn't even clash easily.
The default one is selected in the path variable, i.e, which one is the top of the other (Note that is valid for shell executions).
Alternatively, defaults can be specified in respective IDEs. For me ,I earlier had mingw installed for which codeblocks was configured.But later when I installed Cygwin I modified the path and made it higher priority mingw was perfectly working with codeblocks.