I would like to know if it is possible to code an exe-packer for win32 PE-files. What I mean is a packer like PKLite or XPack for DOS which compress an executable and when starting the packed program it is unpacked into memory and started.
I know there are some problems, e.g. Win32 takes a lot of resources out of the exe like icons and so on. But is it possible to only compress the real code and leave the rest as it is? What else do I have to pay attention to? Is there maybe already a packer?