Root Directory Variable?

Hi,

Sorry if this is a stupid question, but I was wondering if the root directory on windows systems can be any other letter than C:\? If it can, is there any variable like $PROGRAMFILES that points to the root directory? I checked the documentation but couldn't find anything. Any input would be greatly appreciated.

Thanks!

That'd be handy if there was a $SYSTEMDRIVE constant.
You may use this:
ReadEnvStr $0 SYSTEMDRIVE

Thanks a lot Red Wine, that is exactly what I needed!