The windows environment variable PROGRAMFILES will tell you where applications should be installed (by default).
The current user "home" directory is held in the environment variable USERPROFILE or in HOMEDRIVE & HOMEPATH.
Application data is in APPDATA.
All users profile (used for everyone who uses the PC, is ALLUSERSPROFILE
The current user "home" directory is held in the environment variable USERPROFILE or in HOMEDRIVE & HOMEPATH.
Application data is in APPDATA.
All users profile (used for everyone who uses the PC, is ALLUSERSPROFILE