Why is the fPIC switch missing?

[Emmanuelle via Digitalmars-d-learn]

Hello. My problem is exactly what it says on the title: my dmd 
(windows 7, x64) doesn't seem to have -fPIC:

---
dmd -fPIC
Error: unrecognized switch '-fPIC'
       run `dmd` to print the compiler manual
       run `dmd -man` to open browser on manual
---
`dmd --help` also doesn't have anything about fPIC. Sorry if I'm 
being dense but why is that? Is it only available on Linux?

Thank you!