The product is installed to c:\Program Files\Journyx by default. That location is saved as the %WTHOME% environment variable. There is no "sourcing the setup file" under Windows. The following directory locations are relative to %WTHOME%.

jwt\binLocation of the setup file and CLI tools
python\python.exePython language executable
jwt\timesheetApplication Framework modules
jwt\cgiApplication "Screen" modules
jwt\wtlibApplication library directory
jwt\tmpJournyx logging directory
LightTPDLighttpd web server root directory
jwt\tmp\lighttpdLighttpd web server logs
jwt\htdocsStatic web server files
pgsql_dataPostgreSQL data directory
jwt\tmp\pglogsPostgreSQL logs

%WTHOME%\jwt\bin is the directory where most system administrative tasks are performed. A link to open a command prompt in this directory is installed under the Start > Journyx menu.