Enviroment Variables

[acal3000]

Just as the title says What could be a practical usage of the operating system enviroment variables?...

[Joe Forster/STA]

System-specific values. (I assume you're talking about Windows.) Not all Windows installations are in "C:\Windows" or applications in "C:\Program Files". The directory for temporary files can vary, too. The computer name obviously is different from system to system. You can query those values from the Windows API but not in batch files; only environment variables are available there. Unfortunately, Microsoft didn't think it out much (either) so there aren't many environment variables set up by the system. That's one of the reasons why serious programming in batch files is next to impossible. :(