%ProgramFiles% is a variable that refers to the Program Files folder. A typical path is C:\Program Files.
%Temp% is a variable that refers to the temporary folder in the short path form. By default, this is C:\Documents and Settings\[UserName]\Local Settings\Temp\ (Windows NT/2000/XP).
%Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.