Hi There,
PFTW is indeed discontinued, and no longer offered for download from Flexera Software (although I've seen it hosted here and there on the web still, since it was once freely available).
Some other alternatives:
--A customized InstallScript Project
--Your own custom setup.exe bootstrapper (possibly based on the sample in the Windows Platform SDK)
--IExpress (a windows component. Try it out: Start -> Run -> IExpress -> OK)
--Winzip Self Extractor
--7-zip Self Extractor
--Custom NSIS package (Nullsoft Scriptable Install System)
And those are just off the top of my head. Any option where I use the word "Custom" will require a little work to set up the first time, but likely be much less work subsequent times. And reusable, too, if you need to drop in some custom logic prior to running the MSI package at a later date.
Lastly, it's a little-known feature, but if you are editing an InstallShield setup, some changes are allowed by opening the compressed setup.exe in Direct Edit mode. You have to do this by selecting File -> Open -> type *.*, press enter -> Select the Setup.exe file.
Hope this gives you enough options to get started on this!