Change the Default Location for Installing Programs: "Change the Default Location for Installing Programs
AS you know XP uses the C:\Program Files directory as the default base directory into which new programs are installed. However, you can change the default installation drive and/or directory by using a Registry hack. Run the Registry Editor and go to
Look for the value named ProgramFilesDir.
By default, the value will be C:\Program Files.
Edit the value to any valid drive or folder;
Now XP will use that new location as the default installation directory for new programs.This registry hack can be very useful when your c drive is full and you automatically want to change the installing directory.Enjoy this cool windows registry hack"