Start maven with -X option (debug) and examine the beginning of the output. There should be something like this:
...
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from c:\....\apache-maven-3.0.3\conf\settings.xml
[DEBUG] Reading user settings from c:\....\.m2\settings.xml
[DEBUG] Using local repository at C:\....\repository
...
(Original directory names are removed by me)