Changing target for install directory?

Alright, you know how you can change the settings for your browser to automatically save any download to the specific directory you assign it to. Well, how would I manage to do that when it relates to installing new software - WITHOUT manually reassigning the target directory.Default always is the C:/ drive - how would I change it to (i.e. F:/ drive) so it automatically does it with each and every new program that would be installed?Changing target for install directory?
The default install directory is set by the person setting up the installation script - and it's almost always set to C: as the default (since almost all Windows installations have a C drive). You can't set that globally for the computer.