Inside of the ./bin/startxdmcp.bat arround line 30, the script hard codes the variable assignment as such: SET CYGWIN_ROOT=\cygwin This is a non-issue on 32bit installations of Cygwin, but 64 bit seem to install the environment into C:\cygwin64 and fails to properly run. Discovering the prefix or pulling it from another external configuration would allow the script to run properly. There may be other examples of this in other scripts/batch-files. -Jim -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple